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1

Predator-Prey Interactions of Marine Invaders  

Microsoft Academic Search

Predator-prey interactions are among the most fundamental processes shaping the structure and function of ecological communities,\\u000a particularly in marine systems. In the past several decades, it has become clear that humans are interfering considerably\\u000a with these interactions in many marine systems, mainly by removing top predators via harvesting (Myers and Worm 2003), but\\u000a also through biological introductions. Most introduced species

Gil Rilov

2

Mean free-path length theory of predator–prey interactions: Application to juvenile salmon migration  

Microsoft Academic Search

Ecological theory traditionally describes predator–prey interactions in terms of a law of mass action in which the prey mortality rate depends on the density of predators and prey. This simplifying assumption makes population-based models more tractable but ignores potentially important behaviors that characterize predator–prey dynamics. Here, we expand traditional predator–prey models by incorporating directed and random movements of both predators

James J. Anderson; Eliezer Gurarie; Richard W. Zabel

2005-01-01

3

Enhancing species distribution modeling by characterizing predator-prey interactions.  

PubMed

Niche theory is a well-established concept integrating a diverse array of environmental variables and multispecies interactions used to describe species geographic distribution. It is now customary to employ species distribution models (SDMs) that use environmental variables in conjunction with species location information to characterize species' niches and map their geographic ranges. The challenge remains, however, to account for the biotic interactions of species with other community members on which they depend. We show here how to connect species spatial distribution and their dependence with other species by modeling spatially explicit predator-prey interactions, which we call a trophic interaction distribution model (TIDM). To develop the principles, we capitalized on data from Canada lynx (Lynx canadensis) reintroduced into Colorado. Spatial location information for lynx obtained from telemetry was used in conjunction with environmental data to construct an SDM. The spatial locations of lynx-snowshoe hare encounters obtained from snow-tracking in conjunction with environmental data were used to construct a TIDM. The environmental conditions associated with lynx locations and lynx-hare encounters identified through both SDM and TIDM revealed an initial transient phase in habitat use that settled into a steady state. Nevertheless, despite the potential for the SDM to broadly encompass all lynx hunting and nonhunting spatial locations, the spatial extents of the SDM and TIDM differed; about 40% of important lynx-snowshoe hare locations identified in the TIDM were not identified in the lynx-only SDM. Our results encourage greater effort to quantify spatial locations of trophic interactions among species in a community and the associated environmental conditions when attempting to construct models aimed at projecting current and future species geographic distributions. PMID:24640545

Trainor, Anne M; Schmitz, Oswald J; Ivan, Jacob S; Shenk, Tanya M

2014-01-01

4

Habitat-Mediated Predator-Prey Interactions in the Eastern Gulf of Primary Investigator: Doran Mason -NOAA /GLERL  

E-print Network

Habitat-Mediated Predator-Prey Interactions in the Eastern Gulf of Mexico Primary Investigator Sponsors: Florida Sea Grant, National Marine Fisheries Service, Marine Fisheries Initiative- MARFIN-mediated predator-prey interactions and predator growth rate where H is non-consumable habitat (patch reef size

5

PREDATOR-PREY INTERACTIONS IN SCHOOLING FISHES DURING PERIODS OF TWILIGHT: A STUDY OF THE  

E-print Network

PREDATOR-PREY INTERACTIONS IN SCHOOLING FISHES DURING PERIODS OF TWILIGHT: A STUDY of twilight. During morning twilight, individual silversides formed schools, which in some areas moved from water or along the edge of channels throughout the day. During evening twilight, schools left the reef

6

Elevated CO2 Affects Predator-Prey Interactions through Altered Performance  

PubMed Central

Recent research has shown that exposure to elevated carbon dioxide (CO2) affects how fishes perceive their environment, affecting behavioral and cognitive processes leading to increased prey mortality. However, it is unclear if increased mortality results from changes in the dynamics of predator-prey interactions or due to prey increasing activity levels. Here we demonstrate that ocean pCO2 projected to occur by 2100 significantly effects the interactions of a predator-prey pair of common reef fish: the planktivorous damselfish Pomacentrus amboinensis and the piscivorous dottyback Pseudochromis fuscus. Prey exposed to elevated CO2 (880 µatm) or a present-day control (440 µatm) interacted with similarly exposed predators in a cross-factored design. Predators had the lowest capture success when exposed to elevated CO2 and interacting with prey exposed to present-day CO2. Prey exposed to elevated CO2 had reduced escape distances and longer reaction distances compared to prey exposed to present-day CO2 conditions, but this was dependent on whether the prey was paired with a CO2 exposed predator or not. This suggests that the dynamics of predator-prey interactions under future CO2 environments will depend on the extent to which the interacting species are affected and can adapt to the adverse effects of elevated CO2. PMID:23484032

Allan, Bridie J. M.; Domenici, Paolo; McCormick, Mark I.; Watson, Sue-Ann; Munday, Philip L.

2013-01-01

7

Elevated CO2 affects predator-prey interactions through altered performance.  

PubMed

Recent research has shown that exposure to elevated carbon dioxide (CO2) affects how fishes perceive their environment, affecting behavioral and cognitive processes leading to increased prey mortality. However, it is unclear if increased mortality results from changes in the dynamics of predator-prey interactions or due to prey increasing activity levels. Here we demonstrate that ocean pCO2 projected to occur by 2100 significantly effects the interactions of a predator-prey pair of common reef fish: the planktivorous damselfish Pomacentrus amboinensis and the piscivorous dottyback Pseudochromis fuscus. Prey exposed to elevated CO2 (880 µatm) or a present-day control (440 µatm) interacted with similarly exposed predators in a cross-factored design. Predators had the lowest capture success when exposed to elevated CO2 and interacting with prey exposed to present-day CO2. Prey exposed to elevated CO2 had reduced escape distances and longer reaction distances compared to prey exposed to present-day CO2 conditions, but this was dependent on whether the prey was paired with a CO2 exposed predator or not. This suggests that the dynamics of predator-prey interactions under future CO2 environments will depend on the extent to which the interacting species are affected and can adapt to the adverse effects of elevated CO2. PMID:23484032

Allan, Bridie J M; Domenici, Paolo; McCormick, Mark I; Watson, Sue-Ann; Munday, Philip L

2013-01-01

8

Water turbidity affects predator–prey interactions in a fish–damselfly system  

Microsoft Academic Search

Community structure may differ dramatically between clear-water and turbid lakes. These differences have been attributed to\\u000a differences in the cascading effect of fish on prey populations, owing to the reduced efficiency of fish predation in the\\u000a presence of macrophytes. However, recent theoretical ideas suggest that water turbidity may shape predator–prey interactions,\\u000a and it is predicted that prey will relax its

Frank Van de Meutter; Luc De Meester; Robby Stoks

2005-01-01

9

The role of turbidity as a constraint on predator-prey interactions in aquatic environments  

Microsoft Academic Search

Many of the world's most productive aquatic ecosystems usually contain turbid water. Paradoxically, many fish species that\\u000a live in these habitats are also those that often rely on vision to detect their predators and their prey. For these fish,\\u000a turbidity will reduce the distance at which predator-prey interactions occur, and there should be a reduction in the opportunity\\u000a for behavioural

Mark V. Abrahams; Michael G. Kattenfeld

1997-01-01

10

Predator-Prey Interaction between Largemouth Bass and Bluegills as Influenced by Simulated, Submersed Vegetation  

Microsoft Academic Search

Data from the literature suggest that predatory success declines as habitat complexity increases. To explain this phenomenon, we studied the predator-prey interaction between largemouth bass Micropterus salmoides and bluegills Lepomis macrochirus in four laboratory pools (2.4–3.0 m diameter, 0.7 m deep), each with a different density (0, 50, 250, 1,000 stems\\/m) of artificial plant stems. Behavior was quantified for both

Jacqueline F. Savino; Roy A. Stein

1982-01-01

11

Shifts in the Trophic Ecology of Brook Trout Resulting from Interactions with Yellow Perch: An Intraguild Predator-Prey Interaction  

Microsoft Academic Search

In size-structured populations, predator-prey interactions may be preceded by a phase of resource competition earlier in ontogeny, with potential consequences for population dynamics and resource management. We hypothesized that brook trout Salvelinus fontinalis and yellow perch Perca flavescens would compete for shared resources and interact as predator and prey. We used stable isotopes and stomach content analysis to compare the

David R. Browne; Joseph B. Rasmussen

2009-01-01

12

Acoustic mimicry in a predator-prey interaction  

PubMed Central

Mimicry of visual warning signals is one of the keystone concepts in evolutionary biology and has received substantial research attention. By comparison, acoustic mimicry has never been rigorously tested. Visualizing bat–moth interactions with high-speed, infrared videography, we provide empirical evidence for acoustic mimicry in the ultrasonic warning sounds that tiger moths produce in response to echolocating bats. Two species of sound-producing tiger moths were offered successively to naïve, free-flying red and big brown bats. Noctuid and pyralid moth controls were also offered each night. All bats quickly learned to avoid the noxious tiger moths first offered to them, associating the warning sounds with bad taste. They then avoided the second sound-producing species regardless of whether it was chemically protected or not, verifying both Müllerian and Batesian mimicry in the acoustic modality. A subset of the red bats subsequently discovered the palatability of the Batesian mimic, demonstrating the powerful selective force these predators exert on mimetic resemblance. Given these results and the widespread presence of tiger moth species and other sound-producing insects that respond with ultrasonic clicks to bat attack, acoustic mimicry complexes are likely common components of the acoustic landscape. PMID:17517637

Barber, Jesse R.; Conner, William E.

2007-01-01

13

Reciprocal Behavioral Plasticity and Behavioral Types during Predator-Prey Interactions  

PubMed Central

How predators and prey interact has important consequences for population dynamics and community stability. Here we explored how predator-prey interactions are simultaneously affected by reciprocal behavioral plasticity (i.e., plasticity in prey defenses countered by plasticity in predator offenses and vice versa) and consistent individual behavioral variation (i.e., behavioral types) within both predator and prey populations. We assessed the behavior of a predator species (northern pike) and a prey species (three-spined stickleback) during one-on-one encounters. We also measured additional behavioral and morphological traits in each species. Using structural equation modeling, we found that reciprocal behavioral plasticity as well as predator and prey behavioral types influenced how individuals behaved during an interaction. Thus, the progression and ultimate outcome of predator-prey interactions depend on both the dynamic behavioral feedback occurring during the encounter and the underlying behavioral type of each participant. We also examined whether predator behavioral type is underlain by differences in metabolism and organ size. We provide some of the first evidence that behavioral type is related to resting metabolic rate and size of a sensory organ (the eyes). Understanding the extent to which reciprocal behavioral plasticity and intraspecific behavioral variation influence the outcome of species interactions could provide insight into the maintenance of behavioral variation as well as community dynamics. PMID:24231533

McGhee, Katie E.; Pintor, Lauren M.; Bell, Alison M.

2014-01-01

14

Thermal acclimation of interactions: differential responses to temperature change alter predator-prey relationship  

PubMed Central

Different species respond differently to environmental change so that species interactions cannot be predicted from single-species performance curves. We tested the hypothesis that interspecific difference in the capacity for thermal acclimation modulates predator–prey interactions. Acclimation of locomotor performance in a predator (Australian bass, Macquaria novemaculeata) was qualitatively different to that of its prey (eastern mosquitofish, Gambusia holbrooki). Warm (25°C) acclimated bass made more attacks than cold (15°C) acclimated fish regardless of acute test temperatures (10–30°C), and greater frequency of attacks was associated with increased prey capture success. However, the number of attacks declined at the highest test temperature (30°C). Interestingly, escape speeds of mosquitofish during predation trials were greater than burst speeds measured in a swimming arena, whereas attack speeds of bass were lower than burst speeds. As a result, escape speeds of mosquitofish were greater at warm temperatures (25°C and 30°C) than attack speeds of bass. The decline in the number of attacks and the increase in escape speed of prey means that predation pressure decreases at high temperatures. We show that differential thermal responses affect species interactions even at temperatures that are within thermal tolerance ranges. This thermal sensitivity of predator–prey interactions can be a mechanism by which global warming affects ecological communities. PMID:22859598

Grigaltchik, Veronica S.; Ward, Ashley J. W.; Seebacher, Frank

2012-01-01

15

Predator prey interactions of Procambarus clarkii with aquatic macroinvertebrates in single and multiple prey systems  

NASA Astrophysics Data System (ADS)

Understanding the interspecific interactions of Procambarus clarkii with other aquatic macroinvertebrates will help to unveil the mechanisms and processes underlying biological invasiveness. The purpose of this study was to investigate predator-prey interactions of two ontogenic phases of P. clarkii with native and exotic species of aquatic macroinvertebrates at a single and multiple prey level. We performed laboratory experiments to determine the consumption and the behavioral responses of Chironomus riparius, Physa acuta and Corbicula fluminea to P. clarkii. The presence of P. clarkii significantly affected the abundance of C. riparius and P. acuta, but not of C. fluminea whether prey species were provided singly or simultaneously. The consumption of C. riparius by P. clarkii was higher than P. acuta for both crayfish sizes and situations (single/multiple prey systems) and C. fluminea was never consumed. Physa acuta was the only species that exhibited an anti-predator behavior to P. clarkii. Our results show that P. clarkii can have strong consumptive and trait effects on aquatic macroinvertebrate prey at a single and multiple prey level, resulting in differential impacts on different prey species. This study clarifies some aspects of the predator-prey interactions between P. clarkii and native as well as other exotic macroinvertebrate species that have invaded freshwater biocenosis worldwide.

Correia, Alexandra Marçal; Bandeira, Nuno; Anastácio, Pedro Manuel

2005-11-01

16

Predator-prey interactions shape thermal patch use in a newt larvae-dragonfly nymph model.  

PubMed

Thermal quality and predation risk are considered important factors influencing habitat patch use in ectothermic prey. However, how the predator's food requirement and the prey's necessity to avoid predation interact with their respective thermoregulatory strategies remains poorly understood. The recently developed 'thermal game model' predicts that in the face of imminent predation, prey should divide their time equally among a range of thermal patches. In contrast, predators should concentrate their hunting activities towards warmer patches. In this study, we test these predictions in a laboratory setup and an artificial environment that mimics more natural conditions. In both cases, we scored thermal patch use of newt larvae (prey) and free-ranging dragonfly nymphs (predators). Similar effects were seen in both settings. The newt larvae spent less time in the warm patch if dragonfly nymphs were present. The patch use of the dragonfly nymphs did not change as a function of prey availability, even when the nymphs were starved prior to the experiment. Our behavioral observations partially corroborate predictions of the thermal game model. In line with asymmetric fitness pay-offs in predator-prey interactions (the 'life-dinner' principle), the prey's thermal strategy is more sensitive to the presence of predators than vice versa. PMID:23755175

Gvoždík, Lumír; ?ernická, Eva; Van Damme, Raoul

2013-01-01

17

Predicting the effects of ocean acidification on predator-prey interactions: a conceptual framework based on coastal molluscs.  

PubMed

The influence of environmental change on species interactions will affect population dynamics and community structure in the future, but our current understanding of the outcomes of species interactions in a high-CO2 world is limited. Here, we draw upon emerging experimental research examining the effects of ocean acidification on coastal molluscs to provide hypotheses of the potential impacts of high-CO2 on predator-prey interactions. Coastal molluscs, such as oysters, mussels, and snails, allocate energy among defenses, growth, and reproduction. Ocean acidification increases the energetic costs of physiological processes such as acid-base regulation and calcification. Impacted molluscs can display complex and divergent patterns of energy allocation to defenses and growth that may influence predator-prey interactions; these include changes in shell properties, body size, tissue mass, immune function, or reproductive output. Ocean acidification has also been shown to induce complex changes in chemoreception, behavior, and inducible defenses, including altered cue detection and predator avoidance behaviors. Each of these responses may ultimately alter the susceptibility of coastal molluscs to predation through effects on predator handling time, satiation, and search time. While many of these effects may manifest as increases in per capita predation rates on coastal molluscs, the ultimate outcome of predator-prey interactions will also depend on how ocean acidification affects the specified predators, which also exhibit complex responses to ocean acidification. Changes in predator-prey interactions could have profound and unexplored consequences for the population dynamics of coastal molluscs in a high-CO2 ocean. PMID:25070866

Kroeker, Kristy J; Sanford, Eric; Jellison, Brittany M; Gaylord, Brian

2014-06-01

18

Interactive influence of biotic and abiotic cues on the plasticity of preferred body temperatures in a predator-prey system.  

PubMed

The ability to modify phenotypes in response to heterogeneity of the thermal environment represents an important component of an ectotherm's non-genetic adaptive capacity. Despite considerable attention being dedicated to the study of thermally-induced developmental plasticity, whether or not interspecific interactions shape the plastic response in both a predator and its prey remains unknown. We tested several predictions about the joint influence of predator/prey scents and thermal conditions on the plasticity of preferred body temperatures (T (p)) in both actors of this interaction, using a dragonfly nymphs-newt larvae system. Dragonfly nymphs (Aeshna cyanea) and newt eggs (Ichthyosaura alpestris) were subjected to fluctuating cold and warm thermal regimes (7-12 and 12-22°C, respectively) and the presence/absence of a predator or prey chemical cues. Preferred body temperatures were measured in an aquatic thermal gradient (5-33°C) over a 24-h period. Newt T (p) increased with developmental temperature irrespective of the presence/absence of predator cues. In dragonflies, thermal reaction norms for T (p) were affected by the interaction between temperature and prey cues. Specifically, the presence of newt scents in cold regime lowered dragonfly T (p). We concluded that predator-prey interactions influenced thermally-induced plasticity of T (p) but not in a reciprocal fashion. The occurrence of frequency-dependent thermal plasticity may have broad implications for predator-prey population dynamics, the evolution of thermal biology traits, and the consequences of sustaining climate change within ecological communities. PMID:22358997

Smolinský, Radovan; Gvoždík, Lumír

2012-09-01

19

Predator-Prey Interactions of Dictyostelium discoideum and Escherichia coli in Continuous Culture1  

PubMed Central

Dictyostelium discoideum and Escherichia coli were aerobically propagated in mixed continuous culture in a predator-prey relationship, and the effects of temperature and holding times were examined. Oscillations developed in the concentration of glucose, the limiting substrate for E. coli, and in the densities of the two populations, but eventually steady-state populations were reached. The experimental data were analyzed according to the Lotka-Volterra model for prey-predator relationships and by the Monod model for saturation kinetics. A comparison of the adequacy of the two models in describing predation is given. PMID:4555407

Tsuchiya, H. M.; Drake, J. F.; Jost, J. L.; Fredrickson, A. G.

1972-01-01

20

A link between water availability and nesting success mediated by predator-prey interactions in the Arctic.  

PubMed

Although water availability is primarily seen as a factor affecting food availability (a bottom-up process), we examined its effect on predator-prey interactions through an influence on prey behavior (a top-down process). We documented a link between water availability, predation risk, and reproductive success in a goose species (Chen caerulescens atlantica) inhabiting an Arctic environment where water is not considered a limited commodity. To reach water sources during incubation recesses, geese nesting in mesic tundra (low water availability) must move almost four times as far from their nest than those nesting in wetlands, which reduced their ability to defend their nest against predators and led to a higher predation rate. Nesting success was improved in high rainfall years due to increased water availability, and more so for geese nesting in the low water availability habitat. Likewise, nesting success was improved in years where the potential for evaporative water loss (measured by the atmospheric water vapor pressure) was low, presumably because females had to leave their nest less often to drink. Females from water-supplemented nests traveled a shorter distance to drink, and their nesting success was enhanced by 20% compared to the control. This shows that water availability and rainfall can have a strong effect on predator-prey dynamics and that changes in precipitation brought by climate change could have an impact on some Arctic species through a top-down effect. PMID:19323230

Lecomte, Nicolas; Gauthier, Gilles; Giroux, Jean-François

2009-02-01

21

Predator-prey spatial game as a tool to understand the effects of protected areas on harvester-wildlife interactions.  

PubMed

No-take reserves are sometimes implemented for sustainable population harvesting because they offer opportunities for animals to spatially avoid harvesters, whereas harvesters can benefit in return from the reserve spillover. Here, we used the framework of predator-prey spatial games to understand how protected areas shape spatial interactions between harvesters and target species and determine animal mortality. In these spatial games, the "predator" searches for "prey" and matches their habitat use, unless it meets spatial constraints offering the opportunity for prey to avoid the mortality source. However, such prey refuges could attract predators in the surroundings, which questions the potential benefits for prey. We located, in the Geneva Basin (France), hunting dogs and wild boar Sus scrofa L. during hunting seasons with global positioning systems and very-high-frequency collars. We quantified how the proximity of the reserve shaped the matching between both habitat uses using multivariate analyses and linked these patterns to animals' mortality with a Cox regression analysis. Results showed that habitat uses by both protagonists disassociated only when hunters were spatially constrained by the reserve. In response, hunters increased hunting efforts near the reserve boundary, which induced a higher risk exposure for animals settled over the reserve. The mortality of adult wild boar decreased near the reserve as the mismatch between both habitat uses increased. However the opposite pattern was determined for younger individuals that suffered from the high level of hunting close to the reserve. The predator-prey analogy was an accurate prediction of how the protected area modified spatial relationships between harvesters and target species. Prey-searching strategies adopted by hunters around reserves strongly impacted animal mortality and the efficiency of the protected area for this harvested species. Increasing reserve sizes and/or implementing buffer areas with harvesting limitations can dampen this edge effect and helps harvesters to benefit durably from source populations of reserves. Predator-prey spatial games therefore provide a powerful theoretical background for understanding wildlife-harvester spatial interactions and developing substantial application for sustainable harvesting. PMID:22611861

Tolon, Vincent; Martin, Jodie; Dray, Stéphane; Loison, Anne; Fischer, Claude; Baubet, Eric

2012-03-01

22

Hydrodynamic mediation of predator–prey interactions: differential patterns of prey susceptibility and predator success explained by variation in water flow  

Microsoft Academic Search

In most shallow water marine systems, fluid movements vary on scales that may influence local community dynamics both directly, through changes in the abundance of species, and indirectly, by modifying important behaviors of organisms. We examined how differences in current speed affect the outcome of predator–prey interactions for two species of marine benthic predators (knobbed whelks, Busycon carica, and blue

Sean P. Powers; John N. Kittinger

2002-01-01

23

Predator–prey interaction between hatchery-reared Japanese flounder juvenile, Paralichthys olivaceus, and sandy shore crab, Matuta lunaris: daily rhythms, anti-predator conditioning and starvation  

Microsoft Academic Search

Predator–prey interaction between sandy shore crab, Matuta lunaris (Forskål, 1775), and juvenile Japanese flounder, Paralichthys olivaceus (Temminck et Schlegel), was investigated under controlled laboratory conditions. Possibility of training and conditioning hatchery-reared flounder to avoid predators was also examined. Crabs took over 75% of their daily ration at night when they were given access to prey 24 h a day. Large

Mostafa A. R Hossain; Masaru Tanaka; Reiji Masuda

2002-01-01

24

Light-limitation on predator-prey interactions: consequences for metabolism and locomotion of deep-sea cephalopods.  

PubMed

The present study attempts to correlate the metabolism and locomotory behavior of 25 species of midwater Cephalopoda from California and Hawaii with the maximal activities of key metabolic enzymes in various locomotory muscle tissues. Citrate synthase (CS) and octopine dehydrogenase (ODH) activities were used as indicators of aerobic and anaerobic metabolic potential respectively. CS activity in mantle muscle is highly correlated with whole-animal rates of oxygen consumption, whereas ODH activity in mantle muscle is significantly correlated with a species' ability to buffer the acidic end-products of anaerobic metabolism. Both CS and ODH activities in mantle muscle declined strongly with a species' habitat depth. For example, CS and ODH activities ranged respectively from 0.04 units g(-1) and 0.03 units g(-1) in the deep-living squid Joubiniteuthis portieri, to 8.13 units g(-1) and 420 units g(-1) in the epipelagic squid Sthenoteuthis oualaniensis. The relationships between enzymatic activities and depth are consistent with similar patterns observed for whole-animal oxygen consumption. This pattern is believed to result from a relaxation, among deep-living species, in the need for strong locomotory abilities for visual predator/prey interactions; the relaxation is due to light-limitation in the deep sea. Intraspecific scaling patterns for ODH activities may, for species that migrate ontogenetically to great depths, reflect the counteracting effects of body size and light on predator-prey detection distances. When scaled allometrically, enzymatic activities for the giant squid, Architeuthis sp., suggest a fairly active aerobic metabolism but little burst swimming capacity. Interspecific differences in the relative distributions of enzymatic activities in fin, mantle, and arm tissue suggest an increased reliance on fin and arm muscle for locomotion among deep-living species. We suggest that, where high-speed locomotion is not required, more efficient means of locomotion, such as fin swimming or medusoid arm propulsion, are more prevalent. PMID:10786948

Seibel, B A; Thuesen, E V; Childress, J J

2000-04-01

25

Effects of an Infectious Fungus, Batrachochytrium dendrobatidis, on Amphibian Predator-Prey Interactions  

PubMed Central

The effects of parasites and pathogens on host behaviors may be particularly important in predator-prey contexts, since few animal behaviors are more crucial for ensuring immediate survival than the avoidance of lethal predators in nature. We examined the effects of an emerging fungal pathogen of amphibians, Batrachochytrium dendrobatidis, on anti-predator behaviors of tadpoles of four frog species. We also investigated whether amphibian predators consumed infected prey, and whether B. dendrobatidis caused differences in predation rates among prey in laboratory feeding trials. We found differences in anti-predator behaviors among larvae of four amphibian species, and show that infected tadpoles of one species (Anaxyrus boreas) were more active and sought refuge more frequently when exposed to predator chemical cues. Salamander predators consumed infected and uninfected tadpoles of three other prey species at similar rates in feeding trials, and predation risk among prey was unaffected by B. dendrobatidis. Collectively, our results show that even sub-lethal exposure to B. dendrobatidis can alter fundamental anti-predator behaviors in some amphibian prey species, and suggest the unexplored possibility that indiscriminate predation between infected and uninfected prey (i.e., non-selective predation) could increase the prevalence of this widely distributed pathogen in amphibian populations. Because one of the most prominent types of predators in many amphibian systems is salamanders, and because salamanders are susceptible to B. dendrobatidis, our work suggests the importance of considering host susceptibility and behavioral changes that could arise from infection in both predators and prey. PMID:21311771

Han, Barbara A.; Searle, Catherine L.; Blaustein, Andrew R.

2011-01-01

26

Interaction between Coastal and Oceanic Ecosystems of the Western and Central Pacific Ocean through Predator-Prey Relationship Studies  

PubMed Central

The Western and Central Pacific Ocean sustains the highest tuna production in the world. This province is also characterized by many islands and a complex bathymetry that induces specific current circulation patterns with the potential to create a high degree of interaction between coastal and oceanic ecosystems. Based on a large dataset of oceanic predator stomach contents, our study used generalized linear models to explore the coastal-oceanic system interaction by analyzing predator-prey relationship. We show that reef organisms are a frequent prey of oceanic predators. Predator species such as albacore (Thunnus alalunga) and yellowfin tuna (Thunnus albacares) frequently consume reef prey with higher probability of consumption closer to land and in the western part of the Pacific Ocean. For surface-caught-predators consuming reef prey, this prey type represents about one third of the diet of predators smaller than 50 cm. The proportion decreases with increasing fish size. For predators caught at depth and consuming reef prey, the proportion varies with predator species but generally represents less than 10%. The annual consumption of reef prey by the yellowfin tuna population was estimated at 0.8±0.40CV million tonnes or 2.17×1012±0.40CV individuals. This represents 6.1%±0.17CV in weight of their diet. Our analyses identify some of the patterns of coastal-oceanic ecosystem interactions at a large scale and provides an estimate of annual consumption of reef prey by oceanic predators. PMID:22615796

Allain, Valerie; Fernandez, Emilie; Hoyle, Simon D.; Caillot, Sylvain; Jurado-Molina, Jesus; Andrefouet, Serge; Nicol, Simon J.

2012-01-01

27

Coevolution can reverse predator–prey cycles  

PubMed Central

A hallmark of Lotka–Volterra models, and other ecological models of predator–prey interactions, is that in predator–prey cycles, peaks in prey abundance precede peaks in predator abundance. Such models typically assume that species life history traits are fixed over ecologically relevant time scales. However, the coevolution of predator and prey traits has been shown to alter the community dynamics of natural systems, leading to novel dynamics including antiphase and cryptic cycles. Here, using an eco-coevolutionary model, we show that predator–prey coevolution can also drive population cycles where the opposite of canonical Lotka–Volterra oscillations occurs: predator peaks precede prey peaks. These reversed cycles arise when selection favors extreme phenotypes, predator offense is costly, and prey defense is effective against low-offense predators. We present multiple datasets from phage–cholera, mink–muskrat, and gyrfalcon–rock ptarmigan systems that exhibit reversed-peak ordering. Our results suggest that such cycles are a potential signature of predator–prey coevolution and reveal unique ways in which predator–prey coevolution can shape, and possibly reverse, community dynamics. PMID:24799689

Cortez, Michael H.; Weitz, Joshua S.

2014-01-01

28

Coevolution can reverse predator-prey cycles.  

PubMed

A hallmark of Lotka-Volterra models, and other ecological models of predator-prey interactions, is that in predator-prey cycles, peaks in prey abundance precede peaks in predator abundance. Such models typically assume that species life history traits are fixed over ecologically relevant time scales. However, the coevolution of predator and prey traits has been shown to alter the community dynamics of natural systems, leading to novel dynamics including antiphase and cryptic cycles. Here, using an eco-coevolutionary model, we show that predator-prey coevolution can also drive population cycles where the opposite of canonical Lotka-Volterra oscillations occurs: predator peaks precede prey peaks. These reversed cycles arise when selection favors extreme phenotypes, predator offense is costly, and prey defense is effective against low-offense predators. We present multiple datasets from phage-cholera, mink-muskrat, and gyrfalcon-rock ptarmigan systems that exhibit reversed-peak ordering. Our results suggest that such cycles are a potential signature of predator-prey coevolution and reveal unique ways in which predator-prey coevolution can shape, and possibly reverse, community dynamics. PMID:24799689

Cortez, Michael H; Weitz, Joshua S

2014-05-20

29

An ecological regime shift resulting from disrupted predator-prey interactions in Holocene Australia.  

PubMed

The mass extinction events during human prehistory are striking examples of ecological regime shifts, the causes of which are still hotly debated. In Australia, human arrival approximately 50 thousand years ago was associated with the continental-scale extinction of numerous marsupial megafauna species and a permanent change in vegetation structure. An alternative stable state persisted until a second regime shift occurred during the late Holocene, when the largest two remaining marsupial carnivores, the thylacine and devil, disappeared from mainland Australia. These extinctions have been widely attributed to the human-assisted invasion of a competing predator, the dingo. In this unusual case, the simultaneous effects of human "intensification" (population growth and technological advances) and climate change (particularly increased ENSO variability) have been largely overlooked. We developed a dynamic model system capable of simulating the complex interactions between the main predators (humans, thylacines, devils, dingoes) and their marsupial prey (macropods), which we coupled with reconstructions of human population growth and climate change for late-Holocene Australia. Because the strength of important interspecific interactions cannot be estimated directly, we used detailed scenario testing and sensitivity analysis to identify robust model outcomes and investigate competing explanations for the Holocene regime shift. This approach identified human intensification as the most probable cause, while also demonstrating the potential importance of synergies with the effects of climate change. Our models indicate that the prehistoric impact of humans on Australian mammals was not limited to the late Pleistocene (i.e., the megafaunal extinctions) but extended into the late Holocene. PMID:24804453

Prowse, Thomas A A; Johnson, Christopher N; Bradshaw, Corey J A; Brook, Barry W

2014-03-01

30

Phylogeographic Triangulation: Using Predator-Prey-Parasite Interactions to Infer Population History from Partial Genetic Information  

PubMed Central

Phylogeographic studies, which infer population history and dispersal movements from intra-specific spatial genetic variation, require expensive and time-consuming analyses that are not always feasible, especially in the case of rare or endangered species. On the other hand, comparative phylogeography of species involved in close biotic interactions may show congruent patterns depending on the specificity of the relationship. Consequently, the phylogeography of a parasite that needs two hosts to complete its life cycle should reflect population history traits of both hosts. Population movements evidenced by the parasite’s phylogeography that are not reflected in the phylogeography of one of these hosts may thus be attributed to the other host. Using the wild rabbit (Oryctolagus cuniculus) and a parasitic tapeworm (Taenia pisiformis) as an example, we propose comparing the phylogeography of easily available organisms such as game species and their specific heteroxenous parasites to infer population movements of definitive host/predator species, independently of performing genetic analyses on the latter. This may be an interesting approach for indirectly studying the history of species whose phylogeography is difficult to analyse directly. PMID:23209834

Barbosa, A. Marcia; Thode, Guillermo; Real, Raimundo; Feliu, Carlos; Vargas, J. Mario

2012-01-01

31

Ultrasonic predator-prey interactions in water-convergent evolution with insects and bats in air?  

PubMed Central

Toothed whales and bats have independently evolved biosonar systems to navigate and locate and catch prey. Such active sensing allows them to operate in darkness, but with the potential cost of warning prey by the emission of intense ultrasonic signals. At least six orders of nocturnal insects have independently evolved ears sensitive to ultrasound and exhibit evasive maneuvers when exposed to bat calls. Among aquatic prey on the other hand, the ability to detect and avoid ultrasound emitting predators seems to be limited to only one subfamily of Clupeidae: the Alosinae (shad and menhaden). These differences are likely rooted in the different physical properties of air and water where cuticular mechanoreceptors have been adapted to serve as ultrasound sensitive ears, whereas ultrasound detection in water have called for sensory cells mechanically connected to highly specialized gas volumes that can oscillate at high frequencies. In addition, there are most likely differences in the risk of predation between insects and fish from echolocating predators. The selection pressure among insects for evolving ultrasound sensitive ears is high, because essentially all nocturnal predation on flying insects stems from echolocating bats. In the interaction between toothed whales and their prey the selection pressure seems weaker, because toothed whales are by no means the only marine predators placing a selection pressure on their prey to evolve specific means to detect and avoid them. Toothed whales can generate extremely intense sound pressure levels, and it has been suggested that they may use these to debilitate prey. Recent experiments, however, show that neither fish with swim bladders, nor squid are debilitated by such signals. This strongly suggests that the production of high amplitude ultrasonic clicks serve the function of improving the detection range of the toothed whale biosonar system rather than debilitation of prey. PMID:23781206

Wilson, Maria; Wahlberg, Magnus; Surlykke, Annemarie; Madsen, Peter Teglberg

2013-01-01

32

Pesticide impacts on predator-prey interactions across two levels of organisation.  

PubMed

In this study, we aimed to evaluate the effects of a short pulse exposure of the pyrethroid lambda-cyhalothrin (LC) on the predator and anti-predator behaviour of the same species; Gammarus pulex. Predator behaviour, at the level of the individual, was studied in indoor microcosms using video tracking equipment during simultaneous exposure of the predator (G. pulex) and its prey (Leuctra nigra) during 90 min exposure of 1, 6.6 or 62.1 ngL(-1) LC. During an initial 30 min of exposure, the predator and prey organisms were maintained physically separated, and the actual interaction was studied through the subsequent 60 min of exposure. The anti-predator behaviour of G. pulex (drift suppression in response to the presence of brown trout) was studied in outdoor stream channels during a 90 min pulse exposure to LC (7.4 or 79.5 ngL(-1)) with, or without, brown trout. Based on survival curves for L. nigra we found that the mortality rate for L. nigra significantly decreased during exposure to 6.6 and 62.1 ngL(-1) LC (P<0.05 and P<0.001, respectively). We found no significant effects suggesting that G. pulex was repelled by contaminated prey items (P>0.05). We found that the exposure of G. pulex to 7.4 and 79.5 ngL(-1) LC significantly increased drift (from ?0% to ?100% in both treatments; P<0.001) independent of the presence of brown trout (P<0.05). In other words, the natural anti-predator behaviour of G. pulex was overruled by the stress response to LC exposure increasing G. pulex predation risk from drift feeding brown trouts. Our results show that the anti-predator and predator behaviour of G. pulex were significantly changed during exposure to very low and environmentally realistic LC concentrations and exposure duration. The potential implications for the field scenario are discussed. PMID:23891783

Rasmussen, Jes Jessen; Nørum, Ulrik; Jerris, Morten Rygaard; Wiberg-Larsen, Peter; Kristensen, Esben Astrup; Friberg, Nikolai

2013-09-15

33

Seasonal forcing and multi-year cycles in interacting populations: lessons from a predator-prey model.  

PubMed

Many natural systems are subject to seasonal environmental change. As a consequence many species exhibit seasonal changes in their life history parameters--such as a peak in the birth rate in spring. It is important to understand how this seasonal forcing affects the population dynamics. The main way in which seasonal models have been studied is through a two dimensional bifurcation approach. We augment this bifurcation approach with extensive simulation in order to understand the potential solution behaviours for a predator-prey system with a seasonally forced prey growth rate. We consider separately how forcing influences the system when the unforced dynamics have either monotonic decay to the coexistence steady state, or oscillatory decay, or stable limit cycles. The range of behaviour the system can exhibit includes multi-year cycles of different periodicities, parameter ranges with coexisting multi-year cycles of the same or different period as well as quasi-periodicity and chaos. We show that the level of oscillation in the unforced system has a large effect on the range of behaviour when the system is seasonally forced. We discuss how the methods could be extended to understand the dynamics of a wide range of ecological and epidemiological systems that are subject to seasonal changes. PMID:23138231

Taylor, Rachel A; Sherratt, Jonathan A; White, Andrew

2013-12-01

34

Potential impact of low-concentration silver nanoparticles on predator-prey interactions between predatory dragonfly nymphs and Daphnia magna as a prey.  

PubMed

This study investigated the potential impacts of low-concentration citrate-coated silver nanoparticles (citrate-nAg; 2 ?g L(-1) as total Ag) on the interactions of Daphnia magna Straus (as a prey) with the predatory dragonfly ( Anax junius : Odonata) nymph using the behavioral, survival, and reproductive end points. Four different toxicity bioassays were evaluated: (i) horizontal migration; (ii) vertical migration; (iii) 48 h survival; and (iv) 21 day reproduction; using four different treatment combinations: (i) Daphnia + citrate-nAg; (ii) Daphnia + predator; (iii) Daphnia + citrate-nAg + predator; and (iv) Daphnia only (control). Daphnia avoided the predators using the horizontal and vertical movements, indicating that Daphnia might have perceived a significant risk of predation. However, with citrate-nAg + predator treatment, Daphnia response did not differ from control in the vertical migration test, suggesting that Daphnia were unable to detect the presence of predator with citrate-nAg treatment and this may have potential implication on daphnids population structure owing to predation risk. The 48 h survival test showed a significant mortality of Daphnia individuals in the presence of predators, with or without citrate-nAg, in the test environment. Average reproduction of daphnids increased by 185% with low-concentration citrate-nAg treatment alone but was severely compromised in the presence of predators (decreased by 91.3%). Daphnia reproduction was slightly enhanced by approximately 128% with citrate-nAg + predator treatment. Potential mechanisms of these differential effects of low-concentration citrate-nAg, with or without predators, are discussed. Because silver dissolution was minimal, the observed toxicity could not be explained by dissolved Ag alone. These findings offer novel insights into how exposure to low-concentration silver nanoparticles could influence predator-prey interactions in the fresh water systems. PMID:22697289

Pokhrel, Lok R; Dubey, Brajesh

2012-07-17

35

Probability of Detecting Marine Predator-Prey and Species Interactions Using Novel Hybrid Acoustic Transmitter-Receiver Tags  

PubMed Central

Understanding the nature of inter-specific and conspecific interactions in the ocean is challenging because direct observation is usually impossible. The development of dual transmitter/receivers, Vemco Mobile Transceivers (VMT), and satellite-linked (e.g. GPS) tags provides a unique opportunity to better understand between and within species interactions in space and time. Quantifying the uncertainty associated with detecting a tagged animal, particularly under varying field conditions, is vital for making accurate biological inferences when using VMTs. We evaluated the detection efficiency of VMTs deployed on grey seals, Halichoerus grypus, off Sable Island (NS, Canada) in relation to environmental characteristics and seal behaviour using generalized linear models (GLM) to explore both post-processed detection data and summarized raw VMT data. When considering only post-processed detection data, only about half of expected detections were recorded at best even when two VMT-tagged seals were estimated to be within 50–200 m of one another. At a separation of 400 m, only about 15% of expected detections were recorded. In contrast, when incomplete transmissions from the summarized raw data were also considered, the ratio of complete transmission to complete and incomplete transmissions was about 70% for distances ranging from 50–1000 m, with a minimum of around 40% at 600 m and a maximum of about 85% at 50 m. Distance between seals, wind stress, and depth were the most important predictors of detection efficiency. Access to the raw VMT data allowed us to focus on the physical and environmental factors that limit a transceiver’s ability to resolve a transmitter’s identity. PMID:24892286

Baker, Laurie L.; Jonsen, Ian D.; Mills Flemming, Joanna E.; Lidgard, Damian C.; Bowen, William D.; Iverson, Sara J.; Webber, Dale M.

2014-01-01

36

Demographic stochasticity reduces the synchronizing effect of dispersal in predator-prey metapopulations.  

PubMed

Dispersal may affect predator-prey metapopulations by rescuing local sink populations from extinction or by synchronizing population dynamics across the metapopulation, increasing the risk of regional extinction. Dispersal is likely influenced by demographic stochasticity, however, particularly because dispersal rates are often very low in metapopulations. Yet the effects of demographic stochasticity on predator-prey metapopulations are not well known. To that end, I constructed three models of a two-patch predator-prey system. The models constitute a hierarchy of complexity, allowing direct comparisons. Two models included demographic stochasticity (pure jump process [PJP] and stochastic differential equations [SDE]), and the third was deterministic (ordinary differential equations [ODE]). One stochastic model (PJP) treated population sizes as discrete, while the other (SDE) allowed population sizes to change continuously. Both stochastic models only produced synchronized predator-prey dynamics when dispersal was high for both trophic levels. Frequent dispersal by only predators or prey in the PJP and SDE spatially decoupled the trophic interaction, reducing synchrony of the non-dispersive species. Conversely, the ODE generated synchronized predator-prey dynamics across all dispersal rates, except when initial conditions produced anti-phase transients. These results indicate that demographic stochasticity strongly reduces the synchronizing effect of dispersal, which is ironic because demographic stochasticity is often invoked post hoc as a driver of extinctions in synchronized metapopulations. PMID:22919898

Simonis, Joseph L

2012-07-01

37

Anthropogenic resource subsidies decouple predator-prey relationships.  

PubMed

The extent to which resource subsidies affect food web dynamics is poorly understood in anthropogenic landscapes. To better understand how species interactions are influenced by subsidies, we studied breeding birds and nest predators along a rural-to-urban landscape gradient that varied in subsidies provided to generalist predators. We hypothesized that resource subsidies in urban landscapes would decouple predator-prey relationships, as predators switch from natural to anthropogenic foods. From 2004 to 2009, we surveyed nest predators and monitored 2942 nests of five songbird species breeding in 19 mature forest stands in Ohio, USA. Eighteen species were video-recorded depredating nests. Numbers of avian and mammalian nest predators were positively associated with the amount of urban development surrounding forests, with the exception of Brown-headed Cowbirds (Molothrus ater). Although nest survival strongly declined with detections of nest predators in rural landscapes, nest survival and predator numbers were unrelated in urban landscapes. Thus, the strength of interaction between breeding birds and nest predators diminished as landscapes surrounding forested parks became more urbanized. Our work suggests that decoupling of predator-prey relationships can arise when synanthropic predators are heavily subsidized by anthropogenic resources. In this way, human drivers can alter, and completely disarticulate, relationships among species that are well established in more natural systems. PMID:21639056

Rodewald, Amanda D; Kearns, Laura J; Shustack, Daniel P

2011-04-01

38

Does Sex-Selective Predation Stabilize or Destabilize Predator-Prey Dynamics?  

PubMed Central

Background Little is known about the impact of prey sexual dimorphism on predator-prey dynamics and the impact of sex-selective harvesting and trophy hunting on long-term stability of exploited populations. Methodology and Principal Findings We review the quantitative evidence for sex-selective predation and study its long-term consequences using several simple predator-prey models. These models can be also interpreted in terms of feedback between harvesting effort and population size of the harvested species under open-access exploitation. Among the 81 predator-prey pairs found in the literature, male bias in predation is 2.3 times as common as female bias. We show that long-term effects of sex-selective predation depend on the interplay of predation bias and prey mating system. Predation on the ‘less limiting’ prey sex can yield a stable predator-prey equilibrium, while predation on the other sex usually destabilizes the dynamics and promotes population collapses. For prey mating systems that we consider, males are less limiting except for polyandry and polyandrogyny, and male-biased predation alone on such prey can stabilize otherwise unstable dynamics. On the contrary, our results suggest that female-biased predation on polygynous, polygynandrous or monogamous prey requires other stabilizing mechanisms to persist. Conclusions and Significance Our modelling results suggest that the observed skew towards male-biased predation might reflect, in addition to sexual selection, the evolutionary history of predator-prey interactions. More focus on these phenomena can yield additional and interesting insights as to which mechanisms maintain the persistence of predator-prey pairs over ecological and evolutionary timescales. Our results can also have implications for long-term sustainability of harvesting and trophy hunting of sexually dimorphic species. PMID:18628951

Boukal, David S.; Berec, Lud?k; K?ivan, Vlastimil

2008-01-01

39

theoretical population biology 50, 368393 (1996) Lotka's Game in PredatorPrey Theory  

E-print Network

theoretical population biology 50, 368393 (1996) Lotka's Game in PredatorPrey Theory: Linking pulses and the interactions of these wave pulses constitute global dynamics. The results motivate, and ontogeny of organisms. This understanding would both explain and help classify specific systems accor- ding

Wilson, Will

40

SHIFTING PREY SELECTION GENERATES CONTRASTING HERBIVORE DYNAMICS WITHIN A LARGE-MAMMAL PREDATOR–PREY WEB  

Microsoft Academic Search

Shifting prey selection has been identified as a mechanism potentially regulating predator-prey interactions, but it may also lead to different outcomes, especially in more complex systems with multiple prey species available. We assessed changing prey selection by lions, the major predator for 12 large herbivore species in South Africa's Kruger National Park. The database was provided by records of found

Norman Owen-Smith; M. G. L. Mills

2008-01-01

41

A Model-Based Approach to Predicting Predator-Prey & Friend-Foe Relationships in Ant Colonies  

E-print Network

Understanding predator-prey relationships among insects is a challenging task in the domain of insect-colony research. This is due to several factors involved, such as determining whether a particular behavior is the result of a predator-prey interaction, a friend-foe interaction or another kind of interaction. In this paper, we analyze a series of predator-prey and friend-foe interactions in two colonies of carpenter ants to better understand and predict such behavior. Using the data gathered, we have also come up with a preliminary model for predicting such behavior under the specific conditions the experiment was conducted in. In this paper, we present the results of our data analysis as well as an overview of the processes involved.

Narayanaswami, Karthik

2009-01-01

42

The direct and indirect effects of temperature on a predator–prey relationship  

Microsoft Academic Search

Abiotic factors may directly influence community structure by influencing biotic interactions. In aquatic systems, where gape-limited predators are common, abiotic factors that influence organisms' growth rates potentially mediate predator-prey interactions indirectly through effects on prey size. We tested the hypothesis that temperature influences interactions between aquatic size-limited insect predators ( Notonecta kirbyi) and their larval anuran prey (Hyla regilla) beyond

Michael T. Anderson; Joseph M. Kiesecker; Douglas P. Chivers; Andrew R. Blaustein

2001-01-01

43

Coupled predator-prey oscillations in a chaotic food web.  

PubMed

Coupling of several predator-prey oscillations can generate intriguing patterns of synchronization and chaos. Theory predicts that prey species will fluctuate in phase if predator-prey cycles are coupled through generalist predators, whereas they will fluctuate in anti-phase if predator-prey cycles are coupled through competition between prey species. Here, we investigate predator-prey oscillations in a long-term experiment with a marine plankton community. Wavelet analysis of the species fluctuations reveals two predator-prey cycles that fluctuate largely in anti-phase. The phase angles point at strong competition between the phytoplankton species, but relatively little prey overlap among the zooplankton species. This food web architecture is consistent with the size structure of the plankton community, and generates highly dynamic food webs. Continued alternations in species dominance enable coexistence of the prey species through a non-equilibrium 'killing-the-winner' mechanism, as the system shifts back and forth between the two predator-prey cycles in a chaotic fashion. PMID:19845726

Benincà, Elisa; Jöhnk, Klaus D; Heerkloss, Reinhard; Huisman, Jef

2009-12-01

44

Moorea BIOCODE barcode library as a tool for understanding predator-prey interactions: insights into the diet of common predatory coral reef fishes  

NASA Astrophysics Data System (ADS)

Identifying species involved in consumer-resource interactions is one of the main limitations in the construction of food webs. DNA barcoding of prey items in predator guts provides a valuable tool for characterizing trophic interactions, but the method relies on the availability of reference sequences to which prey sequences can be matched. In this study, we demonstrate that the COI sequence library of the Moorea BIOCODE project, an ecosystem-level barcode initiative, enables the identification of a large proportion of semi-digested fish, crustacean and mollusks found in the guts of three Hawkfish and two Squirrelfish species. While most prey remains lacked diagnostic morphological characters, 94% of the prey found in 67 fishes had >98% sequence similarity with BIOCODE reference sequences. Using this species-level prey identification, we demonstrate how DNA barcoding can provide insights into resource partitioning, predator feeding behaviors and the consequences of predation on ecosystem function.

Leray, M.; Boehm, J. T.; Mills, S. C.; Meyer, C. P.

2012-06-01

45

Trophic organisation and predator-prey interactions among commercially exploited demersal finfishes in the coastal waters of the southeastern Arabian Sea  

NASA Astrophysics Data System (ADS)

Trophic interactions in commercially exploited demersal finfishes in the southeastern Arabian Sea of India were studied to understand trophic organization with emphasis on ontogenic diet shifts within the marine food web. In total, the contents of 4716 stomachs were examined from which 78 prey items were identified. Crustaceans and fishes were the major prey groups to most of the fishes. Based on cluster analysis of predator feeding similarities and ontogenic diet shift within each predator, four major trophic guilds and many sub-guilds were identified. The first guild 'detritus feeders' included all size groups of Cynoglossus macrostomus, Pampus argenteus, Leiognathus bindus and Priacanthus hamrur. Guild two, named 'Shrimp feeders', was the largest guild identified and included all size groups of Rhynchobatus djiddensis and Nemipterus mesoprion, medium and large Nemipterus japonicus, P. hamrur and Grammoplites suppositus, small and medium Otolithes cuvieri and small Lactarius lactarius. Guild three, named 'crab and squilla feeders', consisted of few predators. The fourth trophic guild, 'piscivores', was mainly made up of larger size groups of all predators and all size groups of Pseudorhombus arsius and Carcharhinus limbatus. The mean diet breadth and mean trophic level showed strong correlation with ontogenic diet shift. The mean trophic level varied from 2.2 ± 0.1 in large L. bindus to 4.6 ± 0.2 in large Epinephelus diacanthus and the diet breadth from 1.4 ± 0.3 in medium P. argenteus to 8.3 ± 0.2 in medium N. japonicus. Overall, the present study showed that predators in the ecosystem have a strong feeding preference for the sergestid shrimp Acetes indicus, penaeid shrimps, epibenthic crabs and detritus.

Abdurahiman, K. P.; Nayak, T. H.; Zacharia, P. U.; Mohamed, K. S.

2010-05-01

46

Human Activity Helps Prey Win the Predator-Prey Space Race  

Microsoft Academic Search

Predator-prey interactions, including between large mammalian wildlife species, can be represented as a “space race”, where prey try to minimize and predators maximize spatial overlap. Human activity can also influence the distribution of wildlife species. In particular, high-human disturbance can displace large carnivore predators, a trait-mediated direct effect. Predator displacement by humans could then indirectly benefit prey species by reducing

Tyler B. Muhly; Christina Semeniuk; Alessandro Massolo; Laura Hickman; Marco Musiani; Matjaz Perc

2011-01-01

47

A Generic Approach for Obtaining Higher Entertainment in Predator\\/Prey Games  

Microsoft Academic Search

This paper constitutes a sequel to our previous work focused on investigating cooperative behaviors, adaptive learning and on-line interaction towards the generation of entertainment in computer games. A human-verified metric of interest (i.e. player entertainment) of predator\\/prey games and a neuro- evolution on-line learning (i.e. during play) approach are used to serve this purpose. Experiments presented here demonstrate the generality

Georgios N. Yannakakis; John Hallam

48

The stabilizing effects of genetic diversity on predator-prey dynamics  

PubMed Central

Heterogeneity among prey in their susceptibility to predation is a potentially important stabilizer of predator-prey interactions, reducing the magnitude of population oscillations and enhancing total prey population abundance. When microevolutionary responses of prey populations occur at time scales comparable to population dynamics, adaptive responses in prey defense can, in theory, stabilize predator-prey dynamics and reduce top-down effects on prey abundance. While experiments have tested these predictions, less explored are the consequences of the evolution of prey phenotypes that can persist in both vulnerable and invulnerable classes. We tested this experimentally using a laboratory aquatic system composed of the rotifer Brachionus calyciflorus as a predator and the prey Synura petersenii, a colony-forming alga that exhibits genetic variation in its propensity to form colonies and colony size (larger colonies are a defense against predators). Prey populations of either low initial genetic diversity and low adaptive capacity or high initial genetic diversity and high adaptive capacity were crossed with predator presence and absence. Dynamics measured over the last 127 days of the 167-day experiment revealed no effects of initial prey genetic diversity on the average abundance or temporal variability of predator populations. However, genetic diversity and predator presence/absence interactively affected prey population abundance and stability; diversity of prey had no effects in the absence of predators but stabilized dynamics and increased total prey abundance in the presence of predators. The size structure of the genetically diverse prey populations diverged from single strain populations in the presence of predators, showing increases in colony size and in the relative abundance of cells found in colonies. Our work sheds light on the adaptive value of colony formation and supports the general view that genetic diversity and intraspecific trait variation of prey can play a vital role in the short-term dynamics and stability of planktonic predator-prey systems. PMID:25339982

Steiner, Christopher F; Masse, Jordan

2013-01-01

49

Effects of a disease affecting a predator on the dynamics of a predator-prey system.  

PubMed

We study the effects of a disease affecting a predator on the dynamics of a predator-prey system. We couple an SIRS model applied to the predator population, to a Lotka-Volterra model. The SIRS model describes the spread of the disease in a predator population subdivided into susceptible, infected and removed individuals. The Lotka-Volterra model describes the predator-prey interactions. We consider two time scales, a fast one for the disease and a comparatively slow one for predator-prey interactions and for predator mortality. We use the classical "aggregation method" in order to obtain a reduced equivalent model. We show that there are two possible asymptotic behaviors: either the predator population dies out and the prey tends to its carrying capacity, or the predator and prey coexist. In this latter case, the predator population tends either to a "disease-free" or to a "disease-endemic" state. Moreover, the total predator density in the disease-endemic state is greater than the predator density in the "disease-free" equilibrium (DFE). PMID:19063903

Auger, Pierre; McHich, Rachid; Chowdhury, Tanmay; Sallet, Gauthier; Tchuente, Maurice; Chattopadhyay, Joydev

2009-06-01

50

ARTICLE IN PRESS Interactions between ectomycorrhizal symbiosis and uorescent  

E-print Network

ARTICLE IN PRESS U N C O R R EC TED PR O O F Interactions between ectomycorrhizal symbiosis of the ectomycorrhizal symbiosis between an Australian Acacia (A. holosericea) and Pisolithus sp. strain IR100 with HhaI and two with HaeIII endonucleases. The establishment of the ectomycorrhizal symbiosis with A

Thioulouse, Jean

51

Predator-prey systems depend on a prey refuge.  

PubMed

Models of near-exclusive predator-prey systems such as that of the Canadian lynx and snowshoe hare have included factors such as a second prey species, a Holling Type II predator response and climatic or seasonal effects to reproduce sub-sets of six signature patterns in the empirical data. We present an agent-based model which does not require the factors or constraints of previous models to reproduce all six patterns in persistent populations. Our parsimonious model represents a generalised predator and prey species with a small prey refuge. The lack of the constraints of previous models, considered to be important for those models, casts doubt on the current hypothesised mechanisms of exclusive predator-prey systems. The implication for management of the lynx, a protected species, is that maintenance of an heterogeneous environment offering natural refuge areas for the hare is the most important factor for the conservation of this species. PMID:25058806

Chivers, W J; Gladstone, W; Herbert, R D; Fuller, M M

2014-11-01

52

Nash Equilibria in Noncooperative Predator-Prey Games  

SciTech Connect

A noncooperative game governed by a distributed-parameter predator-prey system is considered, assuming that two players control initial conditions for predator and prey, respectively. Existence of a Nash equilibrium is shown under the condition that the desired population profiles and the environmental carrying capacity for the prey are sufficiently small. A conceptual approximation algorithm is proposed and analyzed. Finally, numerical simulations are performed, too.

Ramos, Angel Manuel [Departamento de Matematica Aplicada, Universidad Complutense de Madrid, Plaza de Ciencias 3, 28040 (Spain)], E-mail: Angel_Ramos@mat.ucm.es; Roubicek, Tomas [Mathematical Institute, Charles University, Sokolovska 83, CZ-186 75 Praha 8 and Institute of Information Theory and Automation, Academy of Sciences, Pod vodarenskou vezi 4 (Czech Republic)], E-mail: roubicek@karlin.mff.cuni.cz

2007-09-15

53

Generation of periodic waves by landscape features in cyclic predator-prey systems.  

PubMed Central

The vast majority of models for spatial dynamics of natural populations assume a homogeneous physical environment. However, in practice, dispersing organisms may encounter landscape features that significantly inhibit their movement. We use mathematical modelling to investigate the effect of such landscape features on cyclic predator-prey populations. We show that when appropriate boundary conditions are applied at the edge of the obstacle, a pattern of periodic travelling waves develops, moving out and away from the obstacle. Depending on the assumptions of the model, these waves can take the form of roughly circular 'target patterns' or spirals. This is, to our knowledge, a new mechanism for periodic-wave generation in ecological systems and our results suggest that it may apply quite generally not only to cyclic predator-prey interactions, but also to populations that oscillate for other reasons. In particular, we suggest that it may provide an explanation for the observed pattern of travelling waves in the densities of field voles (Microtus agrestis) in Kielder Forest (Scotland-England border) and of red grouse (Lagopus lagopus scoticus) on Kerloch Moor (northeast Scotland), which in both cases move orthogonally to any large-scale obstacles to movement. Moreover, given that such obstacles to movement are the rule rather than the exception in real-world environments, our results suggest that complex spatio-temporal patterns such as periodic travelling waves are likely to be much more common in the natural world than has previously been assumed. PMID:11886619

Sherratt, J A; Lambin, X; Thomas, C J; Sherratt, T N

2002-01-01

54

THE ROSENZWEIG-MACARTHUR PREDATOR-PREY HAL L. SMITH*  

E-print Network

THE ROSENZWEIG-MACARTHUR PREDATOR-PREY MODEL HAL L. SMITH* SCHOOL OF MATHEMATICAL AND STATISTICAL. It is the per predator kill rate. 1 #12;2 H.L. Smith 0 0.5 1 1.5 2 2.5 3 3.5 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1 that solutions are bounded in the future and therefore are defined for all t 0. #12;4 H.L. Smith Notice that 2

Smith, Hal

55

Optimal-Sustainable Management of Multi-Species Fisheries: Lessons from a Predator-Prey Model  

E-print Network

Optimal-Sustainable Management of Multi-Species Fisheries: Lessons from a Predator-Prey Model):355-377. Please consult that version for citations #12;2 Optimal-Sustainable Management of Multi-Species Fisheries: Lessons from a Predator-Prey Model Abstract: In this paper we define fisheries management as sustainable

Woodward, Richard T.

56

Short-term sublethal hypoxia affects a predator-prey system in northern Adriatic transitional waters  

NASA Astrophysics Data System (ADS)

Predation intensity depends on factors that affect both the predator's ability to locate prey as well as defensive responses by prey to approaching predators. The interactive effects of short-term hypoxia and predation were tested on the survival of two bivalves ( Tapes philippinarum and Musculista senhousia) through laboratory experiments using the crab Carcinus aestuarii as predator. We found M. senhousia to be a focal prey of C. aestuarii but, after non-lethal hypoxia, the crabs' preference for the focal prey was influenced by the presence of the other prey, T. philippinarum. We observed an environmentally-mediated, non-reciprocal indirect interaction between the two prey species, probably caused by differences in specific traits. Identifying the influence of short-term disturbance on predator-prey relationships is critical for predicting the effects of changes in water quality on trophic interactions and food web dynamics in transitional systems.

Munari, Cristina; Mistri, Michele

2012-01-01

57

Predator-prey pursuit-evasion games in structurally complex environments.  

PubMed

Pursuit and evasion behaviors in many predator-prey encounters occur in a geometrically structured environment. The physical structures in the environment impose strong constraints on the perception and behavioral responses of both antagonists. Nevertheless, no experimental or theoretical study has tackled the issue of quantifying the role of the habitat's architecture on the joint trajectories during a predator-prey encounter. In this study, we report the influence of microtopography of forest leaf litter on the pursuit-evasion trajectories of wolf spiders Pardosa sp. attacking the wood cricket Nemobius sylvestris. Fourteen intact leaf litter samples of 1 m × 0.5 m were extracted from an oak-beech forest floor in summer and winter, with later samples having the most recently fallen leaves. Elevation was mapped at a spatial resolution of 0.5 mm using a laser scanner. Litter structuring patterns were identified by height transects and experimental semi-variograms. Detailed analysis of all visible leaf-fragments of one sample enabled us to relate the observed statistical patterns to the underlying geometry of individual elements. Video recording of pursuit-evasion sequences in arenas with flat paper or leaf litter enabled us to estimate attack and fleeing distances as a function of substrate. The compaction index, the length of contiguous flat surfaces, and the experimental variograms showed that the leaf litter was smoother in summer than in winter. Thus, weathering as well as biotic activities compacted and flattened the litter over time. We found good agreement between the size of the structuring unit of leaf litter and the distance over which attack and escape behaviors both were initiated (both ?3 cm). There was a four-fold topographical effect on pursuit-escape sequences; compared with a flat surface, leaf litter (1) greatly reduced the likelihood of launching a pursuit, (2) reduced pursuit and escape distances by half, (3) put prey and predator on par in terms of pursuit and escape distances, and (4) reduced the likelihood of secondary pursuits, after initial escape of the prey, to nearly zero. Thus, geometry of the habitat strongly modulates the rules of pursuit-evasion in predator-prey interactions in the wild. PMID:23720527

Morice, Sylvie; Pincebourde, Sylvain; Darboux, Frédéric; Kaiser, Wilfried; Casas, Jérôme

2013-11-01

58

On the Neimark-Sacker bifurcation in a discrete predator-prey system.  

PubMed

A two-parameter family of discrete models describing a predator-prey interaction is considered, which generalizes a model discussed by Murray, and originally due to Nicholson and Bailey, consisting of two coupled nonlinear difference equations. In contrast to the original case treated by Murray, where the two populations either die out or may display unbounded growth, the general member of this family displays a somewhat wider range of behaviour. In particular, the model has a nontrivial steady state which is stable for a certain range of parameter values, which is explicitly determined, and also undergoes a Neimark-Sacker bifurcation that produces an attracting invariant curve in some areas of the parameter space and a repelling one in others. PMID:22881206

Hone, A N W; Irle, M V; Thurura, G W

2010-11-01

59

Turing patterns and a stochastic individual-based model for predator-prey systems  

NASA Astrophysics Data System (ADS)

Reaction-diffusion theory has played a very important role in the study of pattern formations in biology. However, a group of individuals is described by a single state variable representing population density in reaction-diffusion models and interaction between individuals can be included only phenomenologically. Recently, we have seamlessly combined individual-based models with elements of reaction-diffusion theory. To include animal migration in the scheme, we have adopted a relationship between the diffusion and the random numbers generated according to a two-dimensional bivariate normal distribution. Thus, we have observed the transition of population patterns from an extinction mode, a stable mode, or an oscillatory mode to the chaotic mode as the population growth rate increases. We show our phase diagram of predator-prey systems and discuss the microscopic mechanism for the stable lattice formation in detail.

Nagano, Seido

2012-02-01

60

Shifting prey selection generates contrasting herbivore dynamics within a large-mammal predator-prey web.  

PubMed

Shifting prey selection has been identified as a mechanism potentially regulating predator-prey interactions, but it may also lead to different outcomes, especially in more complex systems with multiple prey species available. We assessed changing prey selection by lions, the major predator for 12 large herbivore species in South Africa's Kruger National Park. The database was provided by records of found carcasses ascribed to kills by lions assembled over 70 years, coupled with counts of changing prey abundance extending over 30 years. Wildebeest and zebra constituted the most favored prey species during the early portion of the study period, while selection for buffalo rose in the south of the park after a severe drought increased their vulnerability. Rainfall had a negative influence on the proportional representation of buffalo in lion kills, but wildebeest and zebra appeared less susceptible to being killed under conditions of low rainfall. Selection by lions for alternative prey species, including giraffe, kudu, waterbuck, and warthog, was influenced by the changing relative abundance and vulnerability of the three principal prey species. Simultaneous declines in the abundance of rarer antelope species were associated with a sharp increase in selection for these species at a time when all three principal prey species were less available. Hence shifting prey selection by lions affected the dynamics of herbivore populations in different ways: promoting contrasting responses by principal prey species to rainfall variation, while apparently being the main cause of sharp declines by alternative prey species under certain conditions. Accordingly, adaptive responses by predators, to both the changing relative abundance of the principal prey species, and other conditions affecting the relative vulnerability of various species, should be taken into account to understand the interactive dynamics of multispecies predator-prey webs. PMID:18481536

Owen-Smith, Norman; Mills, M G L

2008-04-01

61

Foraging and vulnerability traits modify predator-prey body mass allometry: freshwater macroinvertebrates as a case study.  

PubMed

1. Predation is often size selective, but the role of other traits of the prey and predators in their interactions is little known. This hinders our understanding of the causal links between trophic interactions and the structure of animal communities. Better knowledge of trophic traits underlying predator-prey interactions is also needed to improve models attempting to predict food web structure and dynamics from known species traits. 2. We carried out laboratory experiments with common freshwater macroinvertebrate predators (diving beetles, dragonfly and damselfly larvae and water bugs) and their prey to assess how body size and traits related to foraging (microhabitat use, feeding mode and foraging mode) and to prey vulnerability (microhabitat use, activity and escape behaviour) affect predation strength. 3. The underlying predator-prey body mass allometry characterizing mean prey size and total predation pressure was modified by feeding mode of the predators (suctorial or chewing). Suctorial predators fed upon larger prey and had ˜3 times higher mass-specific predation rate than chewing predators of the same size and may thus have stronger effect on prey abundance. 4. Strength of individual trophic links, measured as mortality of the focal prey caused by the focal predator, was determined jointly by the predator and prey body mass and their foraging and vulnerability traits. In addition to the feeding mode, interactions between prey escape behaviour (slow or fast), prey activity (sedentary or active) and predator foraging mode (searching or ambush) strongly affected prey mortality. Searching predators was ineffective in capturing fast-escape prey in comparison with the remaining predator-prey combinations, while ambush predators caused higher mortality than searching predators and the difference was larger in active prey. 5. Our results imply that the inclusion of the commonly available qualitative data on foraging traits of predators and vulnerability traits of prey could substantially increase biological realism of food web descriptions. PMID:23869526

Klecka, Jan; Boukal, David S

2013-09-01

62

Periodic and Chaotic Events in a Discrete Model of Logistic Type for the Competitive Interaction of Two Species  

E-print Network

Two symmetrically coupled logistic equations are proposed to mimic the competitive interaction between two species. The phenomena of coexistence, oscillations and chaos are present in this cubic discrete system. This work, together with two other similar ones recently published by the authors, completes a triptych dedicated to the two-species relationships present in Nature, namely the symbiosis, the predator-prey and the competition. These models can be used as basic ingredients to build up more complex interactions in the ecological networks.

Ricardo Lopez-Ruiz; Daniele Fournier-Prunaret

2005-04-13

63

Supporting Information Appendix for PERSISTENT PREDATOR-PREY DYNAMICS REVEALED BY  

E-print Network

1 1 Supporting Information Appendix for PERSISTENT PREDATOR-PREY DYNAMICS REVEALED concordance unlikely. Most Mississippian durophagous fish remains (diagnostic teeth) and crinoid remains shark teeth and crinoid fossils are therefore likely to have similar taphonomy, eliminating the effects

Kammer, Thomas

64

Parameter Estimation for Predator-Prey Equations Using Hidden Periodic Model  

Microsoft Academic Search

In this paper, we propose a new two-stage estimation (TSE) method for estimating parameters in two species predator-prey model. In the first stage, we use the hidden periodical model in time series analysis to fit the state variable and their derivates, since the solutions to the predator-prey model have periodical properties. To consider the properties of the solutions to the

Xinsheng Ma

2010-01-01

65

Behavioral response races, predator-prey shell games, ecology of fear, and patch use of pumas and their ungulate prey.  

PubMed

The predator-prey shell game predicts random movement of prey across the landscape, whereas the behavioral response race and landscape of fear models predict that there should be a negative relationship between the spatial distribution of a predator and its behaviorally active prey. Additionally, prey have imperfect information on the whereabouts of their predator, which the predator should incorporate in its patch use strategy. I used a one-predator-one-prey system, puma (Puma concolor)-mule deer (Odocoileus hemionus) to test the following predictions regarding predator-prey distribution and patch use by the predator. (1) Pumas will spend more time in high prey risk/low prey use habitat types, while deer will spend their time in low-risk habitats. Pumas should (2) select large forage patches more often, (3) remain in large patches longer, and (4) revisit individual large patches more often than individual smaller ones. I tested these predictions with an extensive telemetry data set collected over 16 years in a study area of patchy forested habitat. When active, pumas spent significantly less time in open areas of low intrinsic predation risk than did deer. Pumas used large patches more than expected, revisited individual large patches significantly more often than smaller ones, and stayed significantly longer in larger patches than in smaller ones. The results supported the prediction of a negative relationship in the spatial distribution of a predator and its prey and indicated that the predator is incorporating the prey's imperfect information about its presence. These results indicate a behavioral complexity on the landscape scale that can have far-reaching impacts on predator-prey interactions. PMID:21058559

Laundré, John W

2010-10-01

66

Predator prey size relationship between Pseudopleuronectes americanus and Carcinus maenas  

NASA Astrophysics Data System (ADS)

Young-of-year flatfish grow through a series of critical periods in which they are vulnerable to different predators, including decapod crustaceans. The purpose of this study was to determine if winter flounder, Pseudopleuronectes americanus, were vulnerable to one such decapod, the green crab, Carcinus maenas, and to determine if vulnerability differed between wild and cultured fish. To examine the predator-prey size relationship, an experiment was conducted in which six cultured and three wild winter flounder size class treatments were tested against six crab size class treatments. Flounder of all size classes were preyed on by all size classes of green crabs; however, mortality was highest when the largest crabs were matched with the smallest flounder. The number of flounder killed per day was significantly higher (31%) in winter flounder <20 mm compared to all other larger fish size classes (4-8%). Additionally, these fish were attacked at a faster rate than any other fish size class. For the 31-60 mm fish size classes tested, more wild fish (11%) were killed per day by crabs than cultured fish (6.3%). These results suggest that in a winter flounder stock enhancement program, only fish >20 mm should be released to promote post-release survival.

Fairchild, E. A.; Howell, W. H.

2000-10-01

67

Predator-Prey Model for A-Ring Haloes  

NASA Astrophysics Data System (ADS)

Cassini ISS, VIMS, UVIS spectroscopy and occultations show bright haloes around the strongest density waves. . We observe opposing effects: both small and large particles are found at the perturbed locations. Based on a predator-prey model for ring dynamics, we offer the following explanation: Cyclic velocity changes cause perturbed regions to reach higher collision speeds at some orbital phases, which preferentially removes small regolith particles; This forms a halo around the ILR; Surrounding particles diffuse back too slowly to erase the effect; Meteoritic bombardment creates fresh ice fragments at the regions of decreased regolith. Our explanation is based on the idea that moon-triggered clumping occurs at perturbed regions in Saturn's rings. Cyclic system trajectories forced around the stable point create both high velocity dispersion and large aggregates at these distances. This explanation supports the view of a triple architecture of ring particles: a broad size distribution of particles; that aggregate into temporary rubble piles; coated by a regolith of dust. The aggregate model can explain the dynamic nature of the rings and the aggregates can renew rings by shielding and recycling fresh ice.

Esposito, L. W.; Madhusudhana, P.; Colwell, J. E.; Sremcevic, M.; Bradley, E. T.

2013-12-01

68

Using an individual-based model to examine the roles of habitat fragmentation and behavior on predator–prey relationships in seagrass landscapes  

Microsoft Academic Search

Seagrasses, which form critical subtidal habitats for marine organisms worldwide, are fragmented via natural processes but\\u000a are increasingly being fragmented and degraded by boating, fishing, and coastal development. We constructed an individual-based\\u000a model to test how habitat fragmentation and loss influenced predator–prey interactions and cohort size for a group of settling\\u000a juvenile blue crabs (Callinectes sapidus Rathbun) in seagrass landscapes.

Kevin A. Hovel; Helen M. Regan

2008-01-01

69

Predator-Prey Model for Haloes in Saturn's Rings  

NASA Astrophysics Data System (ADS)

Particles in Saturn’s rings have a tripartite nature: (1) a broad distribution of fragments from the disruption of a previous moon that accrete into (2) transient aggregates, resembling piles of rubble, covered by a (3) regolith of smaller grains that result from collisions and meteoritic grinding. Evidence for this triple architecture of ring particles comes from a multitude of Cassini observations. In a number of ring locations (including Saturn’s F ring, the shepherded outer edges of rings A and B and at the locations of the strongest density waves) aggregation and dis-aggregation are operating now. ISS, VIMS, UVIS spectroscopy and occultations show haloes around the strongest density waves. Based on a predator-prey model for ring dynamics, we offer the following explanation: •Cyclic velocity changes cause the perturbed regions to reach higher collision speeds at some orbital phases, which preferentially removes small regolith particles; •This forms a bright halo around the ILR, if the forcing is strong enough; •Surrounding particles diffuse back too slowly to erase the effect; they diffuse away to form the halo. The most rapid time scale is for forcing/aggregate growth/disaggregation; then irreversible regolith erosion; diffusion and/or ballistic transport; and slowest, meteoritic pollution/darkening. We observe both smaller and larger particles at perturbed regions. Straw, UVIS power spectral analysis, kittens and equinox objects show the prey (mass aggregates); while the haloes’ VIMS spectral signature, correlation length and excess variance are created by the predators (velocity dispersion) in regions stirred in the rings. Moon forcing triggers aggregation to create longer-lived aggregates that protect their interiors from meteoritic darkening and recycle the ring material to maintain the current purity of the rings. It also provides a mechanism for creation of new moons at resonance locations in the Roche zone, as proposed by Charnoz etal and Canup.

Esposito, Larry W.; Colwell, Joshua; Sremcevic, Miodrag; Madhusudhanan, Prasanna

70

Biocontrol in an impulsive predator-prey model.  

PubMed

We study a model for biological pest control (or "biocontrol") in which a pest population is controlled by a program of periodic releases of a fixed yield of predators that prey on the pest. Releases are represented as impulsive increases in the predator population. Between releases, predator-pest dynamics evolve according to a predator-prey model with some fairly general properties: the pest population grows logistically in the absence of predation; the predator functional response is either of Beddington-DeAngelis type or Holling type II; the predator per capita birth rate is bounded above by a constant multiple of the predator functional response; and the predator per capita death rate is allowed to be decreasing in the predator functional response and increasing in the predator population, though the special case in which it is constant is permitted too. We prove that, when the predator functional response is of Beddington-DeAngelis type and the predators are not sufficiently voracious, then the biocontrol program will fail to reduce the pest population below a particular economic threshold, regardless of the frequency or yield of the releases. We prove also that our model possesses a pest-eradication solution, which is both locally and globally stable provided that predators are sufficiently voracious and that releases occur sufficiently often. We establish, curiously, that the pest-eradication solution can be locally stable whilst not being globally stable, the upshot of which is that, if we delay a biocontrol response to a new pest invasion, then this can change the outcome of the response from pest eradication to pest persistence. Finally, we state a number of specific examples for our model, and, for one of these examples, we corroborate parts of our analysis by numerical simulations. PMID:25195089

Terry, Alan J

2014-10-01

71

Predator-Prey model for haloes in Saturn's A ring  

NASA Astrophysics Data System (ADS)

UVIS SOI reflectance spectra show bright 'haloes' around the locations of some of the strongest resonances in Saturn's A ring (Esposito etal 2005). UV spectra constrain the size and composition of the icy ring particles (Bradley etal 2010, 2012). The correspondence of IR, UV spectroscopy, HSP wavelet analysis indicate that we detect the same phenomenon. We investigate the Janus 2:1. 4:3, 5:3, 6:5 and Mimas 5:3 inner Lindblad resonances as well as at the Mimas 5:3 vertical resonance (bending wave location). Models of ring particle regolith evolution (Elliott and Esposito 2010) indicate the deeper regolith is made of older and purer ice. The strong resonances can cause streamline crowding (Lewis and Stewart 2005) which damps the interparticle velocity, allowing temporary clumps to grow, which in turn increase the velocity, eroding the clumps and releasing smaller particles and regolith (see the predator-prey model of Esposito etal 2012). This cyclic behavior, driven by the resonant perturbation from the moon, can yield collision velocities at particular azimuths greater than 1m/sec, sufficient to erode the aggregates (Blum 2006), exposing older, purer materials: In the perturbed region, collisions erode the regolith, removing smaller particles. The released regolith material settles in the less perturbed neighboring regions. Diffusion spreads these ring particles with smaller regolith into a 'halo'. Thus, the radial location of the strongest resonances can be where we find both large aggregates and disrupted fragments, in a balance maintained by the periodic moon forcing. If this stirring exposes older, and purer ice, the velocity threshold for eroding the aggregates can explain why only the strongest Lindblad resonances show haloes. Diffusion can explain the morphology of these haloes, although they are not well-resolved spatially by UVIS.

Esposito, Larry W.; Bradley, E. Todd; Colwell, Joshua E.; Madhusudhanan, Prasanna; Sremcevic, Miodrag

2013-04-01

72

Human activity helps prey win the predator-prey space race.  

PubMed

Predator-prey interactions, including between large mammalian wildlife species, can be represented as a "space race", where prey try to minimize and predators maximize spatial overlap. Human activity can also influence the distribution of wildlife species. In particular, high-human disturbance can displace large carnivore predators, a trait-mediated direct effect. Predator displacement by humans could then indirectly benefit prey species by reducing predation risk, a trait-mediated indirect effect of humans that spatially decouples predators from prey. The purpose of this research was to test the hypothesis that high-human activity was displacing predators and thus indirectly creating spatial refuge for prey species, helping prey win the "space race". We measured the occurrence of eleven large mammal species (including humans and cattle) at 43 camera traps deployed on roads and trails in southwest Alberta, Canada. We tested species co-occurrence at camera sites using hierarchical cluster and nonmetric multidimensional scaling (NMS) analyses; and tested whether human activity, food and/or habitat influenced predator and prey species counts at camera sites using regression tree analysis. Cluster and NMS analysis indicated that at camera sites humans co-occurred with prey species more than predator species and predator species had relatively low co-occurrence with prey species. Regression tree analysis indicated that prey species were three times more abundant on roads and trails with >32 humans/day. However, predators were less abundant on roads and trails that exceeded 18 humans/day. Our results support the hypothesis that high-human activity displaced predators but not prey species, creating spatial refuge from predation. High-human activity on roads and trails (i.e., >18 humans/day) has the potential to interfere with predator-prey interactions via trait-mediated direct and indirect effects. We urge scientist and managers to carefully consider and quantify the trait-mediated indirect effects of humans, in addition to direct effects, when assessing human impacts on wildlife and ecosystems. PMID:21399682

Muhly, Tyler B; Semeniuk, Christina; Massolo, Alessandro; Hickman, Laura; Musiani, Marco

2011-01-01

73

Ecosystem-based management of predator-prey relationships: piscivorous birds and salmonids.  

PubMed

Predator-prey relationships are often altered as a result of human activities. Where prey are legally protected, conservation action may include lethal predator control. In the Columbia River basin (Pacific Northwest, USA and Canada), piscivorous predators have been implicated in contributing to a lack of recovery of several endangered anadromous salmonids (Oncorhynchus spp.), and lethal and nonlethal control programs have been instituted against both piscine and avian species. To determine the consequences of avian predation, we used a bioenergetics approach to estimate the consumption of salmonid smolts by waterbirds (Common Merganser, California and Ring-billed Gull, Caspian Tern, Double-crested Cormorant) found in the mid-Columbia River from April through August, 2002-2004. We used our model to explore several predator-prey scenarios, including the impact of historical bird abundance, and the effect of preserving vs. removing birds, on smolt abundance. Each year, <1% of the estimated available salmonid smolts (interannual range: 44,830-109,209; 95% CI = 38,000-137,000) were consumed, 85-98% away from dams. Current diet data combined with historical gull abundance at dams suggests that past smolt consumption may have been 1.5-3 times current numbers, depending on the assumed distribution of gulls along the reaches. After the majority (80%) of salmonid smolts have left the study area, birds switch their diet to predominantly juvenile northern pikeminnow (Ptychocheilus oregonensis), which as adults are significant native salmonid predators in the Columbia River. Our models suggest that one consequence of removing birds from the system may be increased pikeminnow abundance, which--even assuming 80% compensatory mortality in juvenile pikeminnow survival--would theoretically result in an annual average savings of just over 180,000 smolts, calculated over a decade. Practically, this suggests that smolt survival could be maximized by deterring birds from the river when smolts are present, allowing bird presence after the diet switch to act as a tool for salmonid-predator control, and conducting adult-pikeminnow control throughout. Our analysis demonstrates that identifying the strength of ecosystem interactions represents a top priority when attempting to manage the abundance of a particular ecosystem constituent, and that the consequences of a single-species view may be counterintuitive, and potentially counterproductive. PMID:18488627

Wiese, Francis K; Parrish, Julia K; Thompson, Christopher W; Maranto, Christina

2008-04-01

74

Novel predator-prey interactions: is resistance futile?  

Microsoft Academic Search

Premise: Prey species may possess inappropriate behavioural, morphological, and\\/or physiological responses to introduced, novel predators. Thus, introduced predators may exert strong selection on prey species. Organisms: Black-capped vireo, Vireo atricapilla, and the fire ant, Solenopsis invicta. Data: Behavioural response of and time-energy budget for parental vireo defence against nest predation by fire ants. Field site: Fort Hood, Texas, an 88,500-hectare

Jennifer E. Smith; Christopher J. Whelan; Steven J. Taylor; Michael L. Denight; Mike M. Stake

2007-01-01

75

Predator-prey interactions, resource depression and patch revisitation  

USGS Publications Warehouse

Generalist predators may be confronted by different types of prey in different patches: sedentary and conspicuous, cryptic (with or without refugia), conspicuous and nonsocial, or conspicuous and social. I argue that, where encounter rates with prey are of most importance, patch revisitation should be a profitable tactic where prey have short 'recovery' times (conspicuous, nonsocial prey), or where anti-predator response (e.g. shoaling) may increase conspicuousness. Predictions are made for how temporal changes in prey encounter rates should affect revisit schedules and feeding rates for the 4 different prey types.

Erwin, R.M.

1989-01-01

76

Interacting Populations. 2.1 Predator/ Prey models  

E-print Network

, the length of a day which has a yearly cycle or the phases of the moon which has a monthly cycle. A function repeats or the number of cycles per unit time. So the phases of the moon has frequency once per 28 days

Haas, Ruth

77

Spatially induced speciation prevents extinction: the evolution of dispersal distance in oscillatory predator-prey models.  

PubMed Central

In a discrete-generation, individual-oriented model of predator-prey interactions that exhibits oscillations, we show that the self-structuring of the populations into spiral waves induces a selection pressure for ever-increasing dispersal distances in both populations. As the dispersal distances increase, the sizes of the spatial patterns increase, until they are too large to fit into the limited space. The patterns are then lost and the predators go extinct. This scenario, is, however, not the only outcome. A second selection pressure induced by the spatial boundary can cause reduction of the dispersal distances. Depending on the relative strengths of the two selection pressures, the predators and prey may speciate to give coexistence between short-dispersing boundary quasi-species and far-dispersing spiral quasi-species. Now, when pattern loss occurs, the predators switch to predating on the boundary prey quasi-species and do not go extinct. Also, if the populations reproduce sexually, local gene flow can inhibit the evolution of increasing dispersal distances, and hence the spatial patterns are not lost. Speciation and coexistence can also occur in the sexually reproducing species. PMID:9470215

Savill, N J; Hogeweg, P

1998-01-01

78

GENERAL: Pattern formation induced by cross-diffusion in a predator prey system  

NASA Astrophysics Data System (ADS)

This paper considers the Holling-Tanner model for predator-prey with self and cross-diffusion. From the Turing theory, it is believed that there is no Turing pattern formation for the equal self-diffusion coefficients. However, combined with cross-diffusion, it shows that the system will exhibit spotted pattern by both mathematical analysis and numerical simulations. Furthermore, asynchrony of the predator and the prey in the space. The obtained results show that cross-diffusion plays an important role on the pattern formation of the predator-prey system.

Sun, Gui-Quan; Jin, Zhen; Liu, Quan-Xing; Li, Li

2008-11-01

79

Computational Science Technical Note CSTN-015 A Zoology of Emergent Patterns in a Predator-Prey Simulation Model  

E-print Network

0 Computational Science Technical Note CSTN-015 A Zoology of Emergent Patterns in a Predator Zoology of Emergent Patterns in a Predator-Prey Simulation Model}, booktitle = {Proceedings of the Sixth CSTN-015 A Zoology of Emergent Patterns in a Predator-Prey Simulation Model K.A. Hawick, H.A. James

Hawick, Ken

80

Landscape heterogeneity shapes predation in a newly restored predator?prey system  

Microsoft Academic Search

Because some native ungulates have lived without top predators for generations, it has been uncertain whether runaway predation would occur when predators are newly restored to these systems. We show that landscape features and vegetation, which influence predator detection and capture of prey, shape large-scale patterns of predation in a newly restored predator-prey system. We analysed the spatial distribution of

Matthew J. Kauffman; Nathan Varley; Douglas W. Smith; Daniel R. Stahler; Daniel R. MacNulty; Mark S. Boyce

2007-01-01

81

Predator-prey relationships and the evolution of colour polymorphism: a comparative analysis in diurnal raptors  

Microsoft Academic Search

Genetically based variation in coloration occurs in populations of many organisms belonging to various taxa, includ- ing birds, mammals, frogs, molluscs, insects and plants. Colour polymorphism has evolved in raptors more often than in any other group of birds, suggesting that predator-prey relationships was a driving evolutionary force. Individuals displaying a new invading colour morph may enjoy an initial foraging

A. ROULIN; M. WINK

2004-01-01

82

Theoretical Population Biology 57, 325 337 (2000) Identifying Predator Prey Processes from  

E-print Network

-fitting to test if typical ecological predator prey time series data, which contain both observation error were obtained. One particular application of this concept is to test alter- native dynamic predator ecological time-series can give rise to wrong identifications. We will also discuss the quality of parameter

Jost, Christian

83

A Time Delay Predator-Prey System with Three-Stage-Structure  

PubMed Central

A predator-prey system was studied that has a discrete delay, stage-structure, and Beddington-DeAngelis functional response, where predator species has three stages, immature, mature, and old age stages. By using of Mawhin's continuous theorem of coincidence degree theory, a sufficient condition is obtained for the existence of a positive periodic solution. PMID:25143982

Gao, Qiaoqin; Jin, Zhen

2014-01-01

84

The Macaroni Lab: A Directed Inquiry Project on Predator-Prey Relationships.  

ERIC Educational Resources Information Center

Presents a directed-inquiry activity to take students one step beyond observation of how living organisms capture prey. Uses a field lab based upon predator-prey relationships to enliven the teaching of food web concepts to non-science-major freshman undergraduates. Can also be used in teaching high school biology students through college science…

Oyler, Michelle; Rivera, John; Roffol, Melanie; Gibson, David J.; Middleton, Beth A.; Mathis, Marilyn

1999-01-01

85

Form of an evolutionary tradeoff affects eco-evolutionary dynamics in a predator-prey system.  

PubMed

Evolution on a time scale similar to ecological dynamics has been increasingly recognized for the last three decades. Selection mediated by ecological interactions can change heritable phenotypic variation (i.e., evolution), and evolution of traits, in turn, can affect ecological interactions. Hence, ecological and evolutionary dynamics can be tightly linked and important to predict future dynamics, but our understanding of eco-evolutionary dynamics is still in its infancy and there is a significant gap between theoretical predictions and empirical tests. Empirical studies have demonstrated that the presence of genetic variation can dramatically change ecological dynamics, whereas theoretical studies predict that eco-evolutionary dynamics depend on the details of the genetic variation, such as the form of a tradeoff among genotypes, which can be more important than the presence or absence of the genetic variation. Using a predator-prey (rotifer-algal) experimental system in laboratory microcosms, we studied how different forms of a tradeoff between prey defense and growth affect eco-evolutionary dynamics. Our experimental results show for the first time to our knowledge that different forms of the tradeoff produce remarkably divergent eco-evolutionary dynamics, including near fixation, near extinction, and coexistence of algal genotypes, with quantitatively different population dynamics. A mathematical model, parameterized from completely independent experiments, explains the observed dynamics. The results suggest that knowing the details of heritable trait variation and covariation within a population is essential for understanding how evolution and ecology will interact and what form of eco-evolutionary dynamics will result. PMID:25336757

Kasada, Minoru; Yamamichi, Masato; Yoshida, Takehito

2014-11-11

86

Bioenergetics-based predator-prey relationships between piscivorous birds and juvenile salmonids in the Columbia River estuary.  

E-print Network

??This dissertation focuses on the predator-prey relationship between two species of avian predators, Caspian terns (Hydroprogne caspia) and double-crested cormorants (Phalacrocorax auritus), and one of… (more)

Lyons, Donald E.

2010-01-01

87

The rainbow bridge: Hamiltonian limits and resonance in predator-prey dynamics  

Microsoft Academic Search

.  ?In the presence of seasonal forcing, the intricate topology of non-integrable Hamiltonian predator-prey models is shown to\\u000a exercise profound effects on the dynamics and bifurcation structure of more realistic schemes which do not admit a Hamiltonian\\u000a formulation. The demonstration of this fact is accomplished by writing the more general models as perturbations of a Hamiltonian\\u000a limit, ?, in which are

Aaron A. King; William M. Schaffer

1999-01-01

88

Frequency-Locking in a Spatially Extended Predator-Prey Model  

NASA Astrophysics Data System (ADS)

The study is concerned with the effect of variable dispersal rates on Turing instability of a spatial Holling—Tanner system. A series of numerical simulations show that the oscillatory Turing pattern can emerge due to period diffusion coefficient. Moreover, we find that when the amplitude is above a threshold, 1 : 1 frequency-locking oscillation can be obtained. The results show that period diffusion coefficient plays an important role on the pattern formation in the predator-prey system.

Yu, Cun-Juan; Tan, Ying-Xin

2011-01-01

89

Effects of the heterogeneous landscape on a predator-prey system  

NASA Astrophysics Data System (ADS)

In order to understand how a heterogeneous landscape affects a predator-prey system, a spatially explicit lattice model consisting of predators, prey, grass, and landscape was constructed. The predators and preys randomly move on the lattice space and the grass grows in its neighboring site according to its growth probability. When predators and preys meet at the same site at the same time, a number of prey, equal to the number of predators are eaten. This rule was also applied to the relationship between the prey and grass. The predator (prey) could give birth to an offspring when it ate prey (grass), with a birth probability. When a predator or prey animal was initially introduced, or newly born, its health state was set at a given high value. This health state decreased by one with every time step. When the state of an animal decreased to less than zero, the animal died and was removed from the system. The heterogeneous landscape was characterized by parameter H, which controlled the heterogeneity according to the neutral model. The simulation results showed that H positively or negatively affected a predator’s survival, while its effect on prey and grass was less pronounced. The results can be understood by the disturbance of the balance between the prey and predator densities in the areas where the animals aggregated.

Lee, Sang-Hee

2010-01-01

90

The rainbow bridge: Hamiltonian limits and resonance in predator-prey dynamics.  

PubMed

In the presence of seasonal forcing, the intricate topology of non-integrable Hamiltonian predator-prey models is shown to exercise profound effects on the dynamics and bifurcation structure of more realistic schemes which do not admit a Hamiltonian formulation. The demonstration of this fact is accomplished by writing the more general models as perturbations of a Hamiltonian limit, ℋ, in which are contained infinite numbers of periodic, quasiperiodic and chaotic motions. From ℋ, there emanates a surface, Gamma, of Nejmark-Sacker bifurcations whereby the annual oscillations induced by seasonality are destabilized. Connecting Gamma and ℋ is a bridge of resonance horns within which invariant motions of the Hamiltonian case persist. The boundaries of the resonance horns are curves of tangent (saddle-node) bifurcations corresponding to subharmonics of the yearly cycle. Associated with each horn is a rotation number which determines the dominant frequency, or "color", of attractors within the horn. When viewed through the necessarily coarse filter of ecological data acquisition, and regardless of their detailed topology, these attractors are often indistinguishable from multi-annual cycles. Because the tips of the horns line up monotonically along Gamma, it further follows that the distribution of observable periods in systems subject to fluctuating parameter values induced, for example, by year-to-year variations in the climate, will often exhibit a discernible central tendency. In short, the bifurcation structure is consistent with the observation of multi-annual cycles in Nature. Fundamentally, this is a consequence of the fact that the bridge between ℋ and Gamma is a rainbow bridge. While the present analysis is principally concerned with the two species case (one predator and one prey), Hamiltonian limits are also observed in other ecological contexts: 2n-species (n predators, n prey) systems and periodically-forced three level food chain models. Hamiltonian limits may thus be common in models involving the destruction of one species by another. Given the oft-commented upon structural instability of Hamiltonian systems and the corresponding lack of regard in which they are held as useful caricatures of ecological interactions, the pivotal role assigned here to Hamiltonian limits constitutes a qualitative break with the conventional wisdom. PMID:10602912

King, A A; Schaffer, W M

1999-11-01

91

Predator–prey relations between age-1+ summer flounder ( Paralichthys dentatus, Linnaeus) and age-0 winter flounder ( Pseudopleuronectes americanus, Walbaum): predator diets, prey selection, and effects of sediments and macrophytes  

Microsoft Academic Search

Laboratory experiments and weekly trammel net surveys in the Navesink River, New Jersey (USA) were used to examine the predator–prey interaction between age-1+ summer flounder (Paralichthys dentatus) and age-0 winter flounder (Pseudopleuronectes americanus). Winter flounder (24–67 mm TL) were the dominant piscine prey of summer flounder (n=95, 252–648 mm TL) collected in trammel nets. We observed a temporal shift in

J. P Manderson; B. A Phelan; A. W Stoner; J Hilbert

2000-01-01

92

Antagonistic evolution in an aposematic predator-prey signaling system.  

PubMed

Warning signals within species, such as the bright colors of chemically defended animals, are usually considered mutualistic, monomorphic traits. Such a view is however increasingly at odds with the growing empirical literature, showing nontrivial levels of signal variation within prey populations. Key to understanding this variation, we argue, could be a recognition that toxicity levels frequently vary within populations because of environmental heterogeneity. Inequalities in defense may undermine mutualistic monomorphic signaling, causing evolutionary antagonism between loci that determine appearance of less well-defended and better defended prey forms within species. In this article, we apply a stochastic model of evolved phenotypic plasticity to the evolution of prey signals. We show that when toxicity levels vary, then antagonistic interactions can lead to evolutionary conflict between alleles at different signaling loci, causing signal evolution, "red queen-like" evolutionary chase, and one or more forms of signaling equilibria. A key prediction is that variation in the way that predators use information about toxicity levels in their attack behaviors profoundly affects the evolutionary characteristics of the prey signaling systems. Environmental variation is known to cause variation in many qualities that organisms signal; our approach may therefore have application to other signaling systems. PMID:25132560

Speed, Michael P; Franks, Daniel W

2014-10-01

93

Dynamics of a Diffusive Predator-Prey Model with General Nonlinear Functional Response  

PubMed Central

We study a diffusive predator-prey model with nonconstant death rate and general nonlinear functional response. Firstly, stability analysis of the equilibrium for reduced ODE system is discussed. Secondly, sufficient and necessary conditions which guarantee the predator and the prey species to be permanent are obtained. Furthermore, sufficient conditions for the global asymptotical stability of the unique positive equilibrium of the system are derived by using the method of Lyapunov function. Finally, we show that there are no nontrivial steady state solutions for certain parameter configuration. PMID:24688422

2014-01-01

94

A Rao-Blackwellized particle filter for joint parameter estimation and biomass tracking in a stochastic predator-prey system.  

PubMed

Functional response estimation and population tracking in predator-prey systems are critical problems in ecology. In this paper we consider a stochastic predator-prey system with a Lotka-Volterra functional response and propose a particle filtering method for: (a) estimating the behavioral parameter representing the rate of effective search per predator in the functional response and (b) forecasting the population biomass using field data. In particular, the proposed technique combines a sequential Monte Carlo sampling scheme for tracking the time-varying biomass with the analytical integration of the unknown behavioral parameter. In order to assess the performance of the method, we show results for both synthetic and observed data collected in an acarine predator-prey system, namely the pest mite Tetranychus urticae and the predatory mite Phytoseiulus persimilis. PMID:24506552

Martín-Fernández, Laura; Gilioli, Gianni; Lanzarone, Ettore; Miguez, Joaquin; Pasquali, Sara; Ruggeri, Fabrizio; Ruiz, Diego P

2014-06-01

95

Spatiotemporal patterns provoked by environmental variability in a predator-prey model.  

PubMed

The emergence of spatiotemporal patterns in the distribution of species is one of the most striking phenomena in ecology and nonlinear science. Since it is known that spatial inhomogeneities can significantly affect the dynamics of ecological populations, in the present paper we investigate the impact of environmental variability on the formation of patterns in a spatially extended predator-prey model. In particular, we utilize a predator-prey system with a Holling III functional response and introduce random spatial variations of the kinetic parameter signifying the intrinsic growth rate of the prey, reflecting the impact of a heterogeneous environment. Our results reveal that in the proximity of the Hopf bifurcation environmental variability is able to provoke pattern formation, whereby the coherence of the patterns exhibits a resonance-like dependence on the variability strength. Furthermore, we show that the phenomenon can only be observed if the spatial heterogeneities exhibit large enough regions with high growth rates of the prey. Our findings thus indicate that variability could be an essential pattern formation mechanism of the populations. PMID:24055250

Fras, Maja; Gosak, Marko

2013-12-01

96

Dynamics of additional food provided predator-prey system with mutually interfering predators.  

PubMed

Use of additional/alternative food source to predators is one of the widely recognised practices in the field of biological control. Both theoretical and experimental works point out that quality and quantity of additional food play a vital role in the controllability of the pest. Theoretical studies carried out previously in this direction indicate that incorporating mutual interference between predators can stabilise the system. Experimental evidence also point out that mutual interference between predators can affect the outcome of the biological control programs. In this article dynamics of additional food provided predator-prey system in the presence of mutual interference between predators has been studied. The mutual interference between predators is modelled using Beddington-DeAngelis type functional response. The system analysis highlights the role of mutual interference on the success of biological control programs when predators are provided with additional food. The model results indicate the possibility of stable coexistence of predators with low prey population levels. This is in contrast to classical predator-prey models wherein this stable co-existence at low prey population levels is not possible. This study classifies the characteristics of biological control agents and additional food (of suitable quality and quantity), permitting the eco-managers to enhance the success rate of biological control programs. PMID:24018292

Prasad, B S R V; Banerjee, Malay; Srinivasu, P D N

2013-11-01

97

The population dynamics of pike, Esox lucius , and perch, Perca fluviatilis , in a simple predator-prey system  

Microsoft Academic Search

The population dynamics and predator-prey relationship of pike, Esox lucius, and perch, Perca fluviatilis, were examined in simple fish communities in two adjacent shallow lakes, Lochs Kinord and Davan, Deeside, Scotland. Few perch survive to age 3 but Z is low for fish > 3 years and perch live up to 17 years. Population fecundity remained relatively high and constant

James W. Treasurer; Roger Owen; Eric Bowers

1992-01-01

98

A Comparison of the Seasonal Movements of Tiger Sharks and Green Turtles Provides Insight into Their Predator-Prey Relationship  

PubMed Central

During the reproductive season, sea turtles use a restricted area in the vicinity of their nesting beaches, making them vulnerable to predation. At Raine Island (Australia), the highest density green turtle Chelonia mydas rookery in the world, tiger sharks Galeocerdo cuvier have been observed to feed on green turtles, and it has been suggested that they may specialise on such air-breathing prey. However there is little information with which to examine this hypothesis. We compared the spatial and temporal components of movement behaviour of these two potentially interacting species in order to provide insight into the predator-prey relationship. Specifically, we tested the hypothesis that tiger shark movements are more concentrated at Raine Island during the green turtle nesting season than outside the turtle nesting season when turtles are not concentrated at Raine Island. Turtles showed area-restricted search behaviour around Raine Island for ?3–4 months during the nesting period (November–February). This was followed by direct movement (transit) to putative foraging grounds mostly in the Torres Straight where they switched to area-restricted search mode again, and remained resident for the remainder of the deployment (53–304 days). In contrast, tiger sharks displayed high spatial and temporal variation in movement behaviour which was not closely linked to the movement behaviour of green turtles or recognised turtle foraging grounds. On average, tiger sharks were concentrated around Raine Island throughout the year. While information on diet is required to determine whether tiger sharks are turtle specialists our results support the hypothesis that they target this predictable and plentiful prey during turtle nesting season, but they might not focus on this less predictable food source outside the nesting season. PMID:23284819

Fitzpatrick, Richard; Thums, Michele; Bell, Ian; Meekan, Mark G.; Stevens, John D.; Barnett, Adam

2012-01-01

99

Differential effects of mercury on activity and swimming endurance in a model aquatic predator-prey system  

SciTech Connect

In addition to direct effects of contaminants on organisms, populations and communities, there may also be indirect or secondary effects related to altered behavior. This study examined the effects of mercury exposure on locomotory behavior in a model predator-prey system of largemouth bass (Micropterus salmoides) and fathead minnows (Pimephales promelas). At both low and high mercury concentrations, there was a significant effect of exposure on unforced activity and swimming endurance in fathead minnows. At all tested mercury concentrations, activity and endurance also were both positively correlated to body length. However, largemouth bass unforced activity and swimming endurance were not affected by exposure to low mercury concentrations. In light of these differential locomotory effects at environmentally relevant mercury concentrations, the potential impact on aquatic predator-prey systems will be discussed.

Benton, M.J.; Carlson, J.K.; Benson, W.H. [Univ. of Mississippi, University, MS (United States)

1994-12-31

100

Dynamic Behavior of Positive Solutions for a Leslie Predator-Prey System with Mutual Interference and Feedback Controls  

PubMed Central

We consider a Leslie predator-prey system with mutual interference and feedback controls. For general nonautonomous case, by using differential inequality theory and constructing a suitable Lyapunov functional, we obtain some sufficient conditions which guarantee the permanence and the global attractivity of the system. For the periodic case, we obtain some sufficient conditions which guarantee the existence, uniqueness, and stability of a positive periodic solution. PMID:24578652

Zhang, Cong; Deng, Chuan-xian

2014-01-01

101

Relaxation oscillation profile of limit cycle in predator-prey Department of Mathematics, National Tsing Hua University, Hsinchu, Taiwan  

E-print Network

= C K V, then we obtain a dimensionless equation: (1.4) du dt = u (1 - u) - muv a + u , dv dt = -dv]. A main idea of later result is to transform (1.4) or a more general predator-prey system into a Lienard equation. Our interest in this article is on the asymptotic behavior of the limit cycle of (1.4) when

Hsu, Sze-Bi

102

Modelling Spatial Interactions in the Arbuscular Mycorrhizal Symbiosis using the Calculus of Wrapped Compartments  

E-print Network

Arbuscular mycorrhiza (AM) is the most wide-spread plant-fungus symbiosis on earth. Investigating this kind of symbiosis is considered one of the most promising ways to develop methods to nurture plants in more natural manners, avoiding the complex chemical productions used nowadays to produce artificial fertilizers. In previous work we used the Calculus of Wrapped Compartments (CWC) to investigate different phases of the AM symbiosis. In this paper, we continue this line of research by modelling the colonisation of the plant root cells by the fungal hyphae spreading in the soil. This study requires the description of some spatial interaction. Although CWC has no explicit feature modelling a spatial geometry, the compartment labelling feature can be effectively exploited to define a discrete surface topology outlining the relevant sectors which determine the spatial properties of the system under consideration. Different situations and interesting spatial properties can be modelled and analysed in such a ligh...

Calcagno, Cristina; Damiani, Ferruccio; Drocco, Maurizio; Sciacca, Eva; Spinella, Salvatore; Troina, Angelo; 10.4204/EPTCS.67.3

2011-01-01

103

Phase diagram of a cyclic predator-prey model with neutral-pair exchange.  

PubMed

In this paper we obtain the phase diagram of a four-species predator-prey lattice model by using the proposed gradient method. We consider cyclic transitions between consecutive states, representing invasion or predation, and allowed the exchange between neighboring neutral pairs. By applying a gradient in the invasion rate parameter one can see, in the same simulation, the presence of two symmetric absorbing phases, composed by neutral pairs, and an active phase that includes all four species. In this sense, the study of a single-valued interface and its fluctuations give the critical point of the irreversible phase transition and the corresponding universality classes. Also, the consideration of a multivalued interface and its fluctuations bring the percolation threshold. We show that the model presents two lines of irreversible first-order phase transition between the two absorbing phases and the active phase. Depending on the value of the system parameters, these lines can converge into a triple point, which is the beginning of a first-order irreversible line between the two absorbing phases, or end in two critical points belonging to the directed percolation universality class. Standard simulations for some characteristic values of the parameters confirm the order of the transitions as determined by the gradient method. Besides, below the triple point the model presents two standard percolation lines in the active phase and above a first-order percolation transition as already found in other similar models. PMID:24032801

Guisoni, Nara C; Loscar, Ernesto S; Girardi, Mauricio

2013-08-01

104

Interacting influence of mycorrhizal symbiosis and competition on plant diversity in tallgrass prairie  

Microsoft Academic Search

In tallgrass prairie, plant species interactions regulated by their associated mycorrhizal fungi may be important forces that\\u000a influence species coexistence and community structure; however, the mechanisms and magnitude of these interactions remain\\u000a unknown. The objective of this study was to determine how interspecific competition, mycorrhizal symbiosis, and their interactions\\u000a influence plant community structure. We conducted a factorial experiment, which incorporated

M. D. Smith; D. C. Hartnett; G. W. T. Wilson

1999-01-01

105

Analysis of a stochastic predator-prey model with applications to intrahost HIV genetic diversity.  

PubMed

During an infection, HIV experiences strong selection by immune system T cells. Recent experimental work has shown that MHC escape mutations form an important pathway for HIV to avoid such selection. In this paper, we study a model of MHC escape mutation. The model is a predator-prey model with two prey, composed of two HIV variants, and one predator, the immune system CD8 cells. We assume that one HIV variant is visible to CD8 cells and one is not. The model takes the form of a system of stochastic differential equations. Motivated by well-known results concerning the short life-cycle of HIV intrahost, we assume that HIV population dynamics occur on a faster time scale then CD8 population dynamics. This separation of time scales allows us to analyze our model using an asymptotic approach. Using this model we study the impact of an MHC escape mutation on the population dynamics and genetic evolution of the intrahost HIV population. From the perspective of population dynamics, we show that the competition between the visible and invisible HIV variants can reach steady states in which either a single variant exists or in which coexistence occurs depending on the parameter regime. We show that in some parameter regimes the end state of the system is stochastic. From a genetics perspective, we study the impact of the population dynamics on the lineages of an HIV sample taken after an escape mutation occurs. We show that the lineages go through severe bottlenecks and that in certain parameter regimes the lineage distribution can be characterized by a Kingman coalescent. Our results depend on methods from diffusion theory and coalescent theory. PMID:22139471

Leviyang, Sivan

2012-12-01

106

Global hopf bifurcation on two-delays leslie-gower predator-prey system with a prey refuge.  

PubMed

A modified Leslie-Gower predator-prey system with two delays is investigated. By choosing ? 1 and ? 2 as bifurcation parameters, we show that the Hopf bifurcations occur when time delay crosses some critical values. Moreover, we derive the equation describing the flow on the center manifold; then we give the formula for determining the direction of the Hopf bifurcation and the stability of bifurcating periodic solutions. Numerical simulations are carried out to illustrate the theoretical results and chaotic behaviors are observed. Finally, using a global Hopf bifurcation theorem for functional differential equations, we show the global existence of the periodic solutions. PMID:24803953

Liu, Qingsong; Lin, Yiping; Cao, Jingnan

2014-01-01

107

A multispecies statistical age-structured model to assess predator-prey balance: application to an intensively managed Lake Michigan pelagic fish community  

USGS Publications Warehouse

Using a Bayesian model fitting approach, we developed a multispecies statistical catch-at-age model to assess trade-offs between predatory demands and prey productivities, focusing on the Lake Michigan pelagic fish community. We assessed these trade-offs in terms of predation mortalities and productivities of alewife (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax) and functional responses of salmonines. Our predation mortality estimates suggest that salmonine consumption has been a major driver of historical fluctuations in prey abundance, with sharp declines in alewife abundance in the 1980s and 2000s coinciding with estimated increases in predation mortalities. While Chinook salmon (Oncorhynchus tshawytscha) were food limited during periods of low alewife abundance, other salmonines appeared to maintain a (near) maximum per-predator consumption across all observed prey densities, suggesting that feedback mechanisms are unlikely to help maintain a balance between predator consumption and prey productivity in Lake Michigan. This study demonstrates that a multispecies modeling approach that combines stock assessment methods with explicit consideration of predator–prey interactions could provide the basis for tactical decision-making from a broader ecosystem perspective.

Tsehaye, Iyob; Jones, Michael L.; Bence, James R.; Brenden, Travis O.; Madenjian, Charles P.; Warner, David M.

2014-01-01

108

Strain-specific functional and numerical responses are required to evaluate impacts on predator–prey dynamics  

PubMed Central

We use strains recently collected from the field to establish cultures; then, through laboratory studies we investigate how among strain variation in protozoan ingestion and growth rates influences population dynamics and intraspecific competition. We focused on the impact of changing temperature because of its well-established effects on protozoan rates and its ecological relevance, from daily fluctuations to climate change. We show, first, that there is considerable inter-strain variability in thermal sensitivity of maximum growth rate, revealing distinct differences among multiple strains of our model species Oxyrrhis marina. We then intensively examined two representative strains that exhibit distinctly different thermal responses and parameterised the influence of temperature on their functional and numerical responses. Finally, we assessed how these responses alter predator–prey population dynamics. We do this first considering a standard approach, which assumes that functional and numerical responses are directly coupled, and then compare these results with a novel framework that incorporates both functional and numerical responses in a fully parameterised model. We conclude that: (i) including functional diversity of protozoa at the sub-species level will alter model predictions and (ii) including directly measured, independent functional and numerical responses in a model can provide a more realistic account of predator–prey dynamics. PMID:23151643

Yang, Zhou; Lowe, Chris D; Crowther, Will; Fenton, Andy; Watts, Phillip C; Montagnes, David J S

2013-01-01

109

Effects of PredatorPrey Interactions and Benthic Habitat Complexity on Selectivity of a Foraging Generalist  

E-print Network

strategies, affecting the preferences and consumption patterns of predators. Yellow perch Perca flavescens compared the prey selection of yellow perch (230­311 mm) foraging on common Great Lakes prey species--in simple and complex benthic habitats. Yellow perch selected alewives in both simple and complex habitats

110

Time-related predator\\/prey interactions between birds and fish in a northern Swedish river  

Microsoft Academic Search

Seasonal and diel activity patterns of mergansers, gulls, and terns along a river in northern Sweden were documented, as were those of their fish prey. The seasonal and diel activity patterns of goosandersMergus merganser and gulls (Larus canus, L. argentatus, andL. fuscus) were closely related to that of the river lampreyLampetra fluviatilis. During the peak spawning of the river lamprey,

Kjell SjiJberg

1989-01-01

111

Mammalian predator-prey interaction in a fragmented landscape: weasels and voles.  

PubMed

The relationship between predators and prey is thought to change due to habitat loss and fragmentation, but patterns regarding the direction of the effect are lacking. The common prediction is that specialized predators, often more dependent on a certain habitat type, should be more vulnerable to habitat loss compared to generalist predators, but actual fragmentation effects are unknown. If a predator is small and vulnerable to predation by other larger predators through intra-guild predation, habitat fragmentation will similarly affect both the prey and the small predator. In this case, the predator is predicted to behave similarly to the prey and avoid open and risky areas. We studied a specialist predator's, the least weasel, Mustela nivalis nivalis, spacing behavior and hunting efficiency on bank voles, Myodes glareolus, in an experimentally fragmented habitat. The habitat consisted of either one large habitat patch (non-fragmented) or four small habitat patches (fragmented) with the same total area. The study was replicated in summer and autumn during a year with high avian predation risk for both voles and weasels. As predicted, weasels under radio-surveillance killed more voles in the non-fragmented habitat which also provided cover from avian predators during their prey search. However, this was only during autumn, when the killing rate was also generally high due to cold weather. The movement areas were the same for both sexes and both fragmentation treatments, but weasels of both sexes were more prone to take risks in crossing the open matrix in the fragmented treatment. Our results support the hypothesis that habitat fragmentation may increase the persistence of specialist predator and prey populations if predators are limited in the same habitat as their prey and they share the same risk from avian predation. PMID:23728797

Haapakoski, Marko; Sundell, Janne; Ylönen, Hannu

2013-12-01

112

PREDATOR-PREY INTERACTIONS BETWEEN EAGLES AND CACKLING CANADA AND ROSS' GEESE DURING WINTER IN CALIFORNIA  

Microsoft Academic Search

Cackling Geese (Brunta canadensis minima) were preyed on heavily in northeastern California by Golden Eagles (Aquila chysaetos) and less commonly by Bald Eagles (Haliaeetus Zeucocephalus) in 19851990. Eagle predation on Cackling Geese was minimal in other wintering locations in California. In the Klamath Basin, eagles killed Cackling Geese most frequently soon (

SCOTT R. MCWILLIAMS; JON P. DUNN; DENNIS G. RAVELING

1994-01-01

113

Time-related predator/prey interactions between birds and fish in a northern Swedish river.  

PubMed

Seasonal and diel activity patterns of mergansers, gulls, and terns along a river in northern Sweden were documented, as were those of their fish prey. The seasonal and diel activity patterns of goosandersMergus merganser and gulls (Larus canus, L. argentatus, andL. fuscus) were closely related to that of the river lampreyLampetra fluviatilis. During the peak spawning of the river lamprey, birds showed a nocturnal peak in fishing activity. During the summer solstice, birds were active for 24 h. The activity patterns of red-breasted merganserMergus serrator, ternsSterna spp., and three-spined sticklebacksGasterosteus aculeatus were also similar. Activity pattern of the prey apparently influenced breeding time, diel activity and foraging area of the twoMergus species. Social relations between gulls probably corrdinated their peak in fishing, which coincided with the time lampreys were most efficiently exploited. PMID:23494338

Sjöberg, K

1989-03-01

114

Predator-prey interactions of salmon in the plume and near-shore ocean  

E-print Network

at intermediate scales Taxonomic or Trophic Scales Food competition can occur at multiple scales: Within stock and hatchery Columbia River fish in ocean · Trophic position of salmon in NCC · Information gaps and potential corridors (1000 km / months) Food competition mostly happens at the patch scale Most sampling occurs

115

Stream ecological processes are modeled through a simple predator-prey model, which reproduces benthic algae and macro-invertebrates dynamics.  

E-print Network

reproduces benthic algae and macro-invertebrates dynamics. Algae biomass = growth - death loss - predation influences on algae and macro-invertebrates dynamics will be introduced in the predator-prey model: - at increasing flow velocity high nutrient availability, algae erosion and macro-invertebrate drag

116

Consequences of a refuge for the predator-prey1 dynamics of a wolf-elk system in Banff National2  

E-print Network

Park, Alberta, Canada3 4 Joshua F. Goldberga , Mark Hebblewhitea , John Bardsleyb 5 a ­ Wildlife on predator-prey dynamics, including36 promoting stability through spatial structure, creating dynamic shifts in response to predation, whereby individuals from50 surrounding areas shift their habitat use

Bardsley, John

117

Group-Size Selection for a Parameterized Class of Predator-Prey Jean-Pierre de la Croix and Magnus Egerstedt  

E-print Network

Group-Size Selection for a Parameterized Class of Predator-Prey Models Jean-Pierre de la Croix the appropriate group sizes for a team of predators by varying environmental and operational conditions carousel, where up to 15 individuals encircle the prey and then gradually shrink the encirclement in order

Egerstedt, Magnus

118

The dynamics of a Lotka-Volterra predator-prey model with state dependent impulsive harvest for predator.  

PubMed

According to the economic and biological aspects of renewable resources management, we propose a Lotka-Volterra predator-prey model with state dependent impulsive harvest. By using the Poincaré map, some conditions for the existence and stability of positive periodic solution are obtained. Moreover, we show that there is no periodic solution with order larger than or equal to three under some conditions. Numerical results are carried out to illustrate the feasibility of our main results. The bifurcation diagrams of periodic solutions are obtained by using the numerical simulations, and it is shown that a chaotic solution is generated via a cascade of period-doubling bifurcations, which implies that the presence of pulses makes the dynamic behavior more complex. PMID:19523503

Nie, Linfei; Teng, Zhidong; Hu, Lin; Peng, Jigen

2009-11-01

119

Bifurcation analysis and dimension reduction of a predator-prey model for the L-H transition  

SciTech Connect

The L-H transition denotes a shift to an improved confinement state of a toroidal plasma in a fusion reactor. A model of the L-H transition is required to simulate the time dependence of tokamak discharges that include the L-H transition. A 3-ODE predator-prey type model of the L-H transition is investigated with bifurcation theory of dynamical systems. The analysis shows that the model contains three types of transitions: an oscillating transition, a sharp transition with hysteresis, and a smooth transition. The model is recognized as a slow-fast system. A reduced 2-ODE model consisting of the full model restricted to the flow on the critical manifold is found to contain all the same dynamics as the full model. This means that all the dynamics in the system is essentially 2-dimensional, and a minimal model of the L-H transition could be a 2-ODE model.

Dam, Magnus; Brøns, Morten [Department of Applied Mathematics and Computer Science, Technical University of Denmark, DK-2800 Kgs. Lyngby (Denmark)] [Department of Applied Mathematics and Computer Science, Technical University of Denmark, DK-2800 Kgs. Lyngby (Denmark); Juul Rasmussen, Jens; Naulin, Volker [Association Euratom-DTU, Department of Physics, Technical University of Denmark, DTU Risø Campus, DK-4000 Roskilde (Denmark)] [Association Euratom-DTU, Department of Physics, Technical University of Denmark, DTU Risø Campus, DK-4000 Roskilde (Denmark); Xu, Guosheng [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)] [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)

2013-10-15

120

Predator-Prey Oscillations and Zonal Flow-Induced Turbulence Suppression Preceding the L-H Transition  

NASA Astrophysics Data System (ADS)

Understanding the L- to H-mode transition and the density/rotation dependence of the H-mode power threshold is important for the design and predictive modeling of burning plasma experiments. We present here direct experimental evidence of the importance of predator-prey oscillations and turbulence/transport regulation by low frequency zonal flows (ZFs) at the L-H transition. Near the H-mode power threshold, a narrow oscillating flow layer develops at/inside the separatrix in a neutral beam-heated DIII-D plasma. Toroidal and radial correlation of the ExB velocity, as measured by Doppler backscattering (DBS), increase at the transition to this ``dithering'' state. The observed oscillation is consistent with a radially propagating ZF with a frequency much below the expected local GAM frequency. Periodic turbulence suppression due to ZF shearing is first observed when the turbulence decorrelation rate decreases sharply (within 0.1,ms) at the transition to the dithering state and the increasing ZF shearing rate locally surpasses the decorrelation rate. The flow layer then expands radially inwards. The ZF amplitude lags the density fluctuation amplitude by 90^o. The ``final" H-mode transition (sustained turbulence/transport reduction) appears linked to increasing equilibrium flow shear due to the increasing ion pressure gradient. Both features are consistent with the predator-prey model of the L-H transition [1]. The transition dynamics is revealed with high time (<1,s) and spatial resolution (<0.5,cm), combining eight channel and five channel DBS systems, separated 180^o toroidally, with fast profile reflectometry. 3pt [1] E.J. Kim and P.H. Diamond, Phys. Rev. Lett. 90, 185006 (2003).

Schmitz, L.

2011-11-01

121

Impairment of O-antigen production confers resistance to grazing in a model amoeba-cyanobacterium predator-prey system  

PubMed Central

The grazing activity of predators on photosynthetic organisms is a major mechanism of mortality and population restructuring in natural environments. Grazing is also one of the primary difficulties in growing cyanobacteria and other microalgae in large, open ponds for the production of biofuels, as contaminants destroy valuable biomass and prevent stable, continuous production of biofuel crops. To address this problem, we have isolated a heterolobosean amoeba, HGG1, that grazes upon unicellular and filamentous freshwater cyanobacterial species. We have established a model predator–prey system using this amoeba and Synechococcus elongatus PCC 7942. Application of amoebae to a library of mutants of S. elongatus led to the identification of a grazer-resistant knockout mutant of the wzm ABC O-antigen transporter gene, SynPCC7942_1126. Mutations in three other genes involved in O-antigen synthesis and transport also prevented the expression of O-antigen and conferred resistance to HGG1. Complementation of these rough mutants returned O-antigen expression and susceptibility to amoebae. Rough mutants are easily identifiable by appearance, are capable of autoflocculation, and do not display growth defects under standard laboratory growth conditions, all of which are desired traits for a biofuel production strain. Thus, preventing the production of O-antigen is a pathway for producing resistance to grazing by certain amoebae. PMID:23012457

Simkovsky, Ryan; Daniels, Emy F.; Tang, Karen; Huynh, Stacey C.; Golden, Susan S.; Brahamsha, Bianca

2012-01-01

122

The Helmholtz Theorem for the Lotka-Volterra Equation, the Extended Conservation Relation, and Stochastic Predator-Prey Dynamics  

E-print Network

We carry out a mathematical analysis, \\`{a} la Helmholtz's and Boltzmann's 1884 studies of monocyclic Newtonian mechanics, for the Lotka-Volterra (LV) equation exhibiting oscillatory predator-prey dynamics. One of the important features of the latter system, absent in the classical mechanical model, is a natural stochastic dynamic formulation of which the LV equation is the infinite population limit. The invariant density for the stochastic dynamics plays a central role in the deterministic LV dynamics. We show how the conservation law along a single trajectory can be extended to incorporate both variations in model parameter $\\alpha$ and in the initial conditions: Helmholtz's theorem establishes a broadly valid conservation law in a class of ecological dynamics. We analyze the relationships among mean ecological activeness $\\theta$, quantities characterizing dynamic ranges of populations $\\mathcal{A}$ and $\\alpha$, and the ecological force $F_{\\alpha}$. The analysis identifies an entire orbit as a stationary ecology, and establishes the notion of an "equation of ecological state". Studies of the stochastic dynamics with finite populations show the LV equation as the rubust, fast cyclic underlying behavior. The mathematical narrative provides a novel way of capturing long-term ecological dynamical behavior with an emergent conservative ecology.

Yi-An Ma; Hong Qian

2014-05-16

123

Food-Web Structure in Relation to Environmental Gradients and Predator-Prey Ratios in Tank-Bromeliad Ecosystems  

PubMed Central

Little is known of how linkage patterns between species change along environmental gradients. The small, spatially discrete food webs inhabiting tank-bromeliads provide an excellent opportunity to analyse patterns of community diversity and food-web topology (connectance, linkage density, nestedness) in relation to key environmental variables (habitat size, detrital resource, incident radiation) and predators:prey ratios. We sampled 365 bromeliads in a wide range of understorey environments in French Guiana and used gut contents of invertebrates to draw the corresponding 365 connectance webs. At the bromeliad scale, habitat size (water volume) determined the number of species that constitute food-web nodes, the proportion of predators, and food-web topology. The number of species as well as the proportion of predators within bromeliads declined from open to forested habitats, where the volume of water collected by bromeliads was generally lower because of rainfall interception by the canopy. A core group of microorganisms and generalist detritivores remained relatively constant across environments. This suggests that (i) a highly-connected core ensures food-web stability and key ecosystem functions across environments, and (ii) larger deviations in food-web structures can be expected following disturbance if detritivores share traits that determine responses to environmental changes. While linkage density and nestedness were lower in bromeliads in the forest than in open areas, experiments are needed to confirm a trend for lower food-web stability in the understorey of primary forests. PMID:23977128

Dezerald, Olivier; Leroy, Celine; Corbara, Bruno; Carrias, Jean-Francois; Pelozuelo, Laurent; Dejean, Alain; Cereghino, Regis

2013-01-01

124

Indirect Allee Effect, Bistability and Chaotic Oscillations in a Predator-Prey Discrete Model of Logistic Type  

E-print Network

A cubic discrete coupled logistic equation is proposed to model the predator-prey problem. The coupling depends on the population size of both species and on a positive constant $\\lambda$, which could depend on the prey reproduction rate and on the predator hunting strategy. Different dynamical regimes are obtained when $\\lambda$ is modified. For small $\\lambda$, the species become extinct. For a bigger $\\lambda$, the preys survive but the predators extinguish. Only when the prey population reaches a critical value then predators can coexist with preys. For increasing $\\lambda$, a bistable regime appears where the populations apart of being stabilized in fixed quantities can present periodic, quasiperiodic and chaotic oscillations. Finally, bistability is lost and the system settles down in a steady state, or, for the biggest permitted $\\lambda$, in an invariant curve. We also present the basins for the different regimes. The use of the critical curves lets us determine the influence of the zones with different number of first rank preimages in the bifurcation mechanisms of those basins.

Ricardo Lopez-Ruiz; Daniele Fournier-Prunaret

2004-06-11

125

Man-Computer Symbiosis Through Interactive Graphics: A Survey and Identification of Critical Research Areas.  

ERIC Educational Resources Information Center

The purpose of this report was to determine the research areas that appear most critical to achieving man-computer symbiosis. An operational definition of man-computer symbiosis was developed by: (1) reviewing and summarizing what others have said about it, and (2) attempting to distinguish it from other types of man-computer relationships. From…

Knoop, Patricia A.

126

Consequences of a Refuge for the Predator-Prey Dynamics of a Wolf-Elk System in Banff National Park, Alberta, Canada  

PubMed Central

Refugia can affect predator-prey dynamics via movements between refuge and non-refuge areas. We examine the influence of a refuge on population dynamics in a large mammal predator-prey system. Wolves (Canis lupus) have recolonized much of their former range in North America, and as a result, ungulate prey have exploited refugia to reduce predation risk with unknown impacts on wolf-prey dynamics. We examined the influence of a refuge on elk (Cervus elaphus) and wolf population dynamics in Banff National Park. Elk occupy the Banff townsite with little predation, whereas elk in the adjoining Bow Valley experience higher wolf predation. The Banff refuge may influence Bow Valley predator-prey dynamics through source-sink movements. To test this hypothesis, we used 26 years of wolf and elk population counts and the Delayed Rejection Adaptive Metropolis Markov chain Monte Carlo method to fit five predator-prey models: 1) with no source-sink movements, 2) with elk density-dependent dispersal from the refuge to the non-refuge, 3) with elk predation risk avoidance movements from the non-refuge to the refuge, 4) with differential movement rates between refuge and non-refuge, and 5) with short-term, source-sink wolf movements. Model 1 provided the best fit of the data, as measured by Akaike Information Criterion (AIC). In the top model, Banff and Bow Valley elk had median growth rates of 0.08 and 0.03 (95% credibility intervals [CIs]: 0.027–0.186 and 0.001–0.143), respectively, Banff had a median carrying capacity of 630 elk (95% CI: 471.9–2676.9), Bow Valley elk had a median wolf encounter rate of 0.02 (95% CI: 0.013–0.030), and wolves had a median death rate of 0.23 (95% CI: 0.146–0.335) and a median conversion efficiency of 0.07 (95% CI: 0.031–0.124). We found little evidence for potential source-sink movements influencing the predator-prey dynamics of this system. This result suggests that the refuge was isolated from the non-refuge. PMID:24670632

Goldberg, Joshua F.; Hebblewhite, Mark; Bardsley, John

2014-01-01

127

Tadpole–odonate larvae interactions: influence of body size and diel rhythm  

Microsoft Academic Search

Several studies have shown that prey and predator body size may affect the outcome of predator–prey interactions. However,\\u000a few studies have taken in account the changes on predator–prey interactions over 24 h. In a tropical freshwater system I evaluated\\u000a how predator and prey size, and their diel rhythm in activity influenced the interaction between Physalaemus pustulosus tadpoles and dragonfly larvae. Tadpoles

Fabián Gastón Jara

2008-01-01

128

Multitrophic interactions in wetlands infested by an invasive species Lythrum salicaria L.  

E-print Network

??This dissertation examined insect-plant, predator-prey, and predator-predator interactions as they relate to the invasive plant species Lythrum salicaria L. The first study determined the suitability… (more)

Carrion, Bethzayda Matos

2005-01-01

129

Diffusion-limited predator-prey dynamics in Euclidean environments: an allometric individual-based model.  

PubMed

We claim that diffusion-limited rates of reaction can be an explanation for the altered population dynamics predicted by models incorporating local interactions and limited individual mobility. We show that the predictions of a spatially explicit, individual-based model result from reduced rates of predation and reproduction caused by limited individual mobility and patchiness. When these reduced rates are used in a mean-field model, there is better agreement with the predictions of the simulation model incorporating local interactions. We also explain previous findings regarding the effects of dimensionality on population dynamics in light of diffusion-limited reactions and Pólya random walks. In particular, we demonstrate that 3D systems are better "stirred" than 2D systems and consequently have a reduced tendency for diffusion-limited interaction rates. PMID:11162786

Cuddington, K M; Yodzis, P

2000-12-01

130

The anatomy of predator–prey dynamics in a changing climate  

Microsoft Academic Search

Summary 1. Humans are increasingly influencing global climate and regional predator assem- blages, yet a mechanistic understanding of how climate and predation interact to affect fluctuations in prey populations is currently lacking. 2. Here we develop a modelling framework to explore the effects of different predation strategies on the response of age-structured prey populations to a changing climate. 3. We

CHRISTOPHER C. WILMERS; ERIC POST; ALAN HASTINGS

2007-01-01

131

Advances in molecular ecology: tracking trophic links through predator-prey food-webs  

Microsoft Academic Search

Summary 1. It is not always possible to track trophic interactions between predators and prey by direct observation. This is especially true when observing small or elusive animals with cryptic food-web ecology. Gut and\\/or faecal analysis can sometimes allow prey remains to be identified visually but is only possible when a component of the diet is resistant to digestion. In

S. K. SHEPPARD; J. D. HARWOOD

2005-01-01

132

Collective behavior and predation success in a predator-prey model inspired by hunting bats  

NASA Astrophysics Data System (ADS)

We establish an agent-based model to study the impact of prey behavior on the hunting success of predators. The predators and prey are modeled as self-propelled particles moving in a three-dimensional domain and subject to specific sensing abilities and behavioral rules inspired by bat hunting. The predators randomly search for prey. The prey either align velocity directions with peers, defined as "interacting" prey, or swarm "independently" of peer presence; both types of prey are subject to additive noise. In a simulation study, we find that interacting prey using low noise have the maximum predation avoidance because they form localized large groups, while they suffer high predation as noise increases due to the formation of broadly dispersed small groups. Independent prey, which are likely to be uniformly distributed in the domain, have higher predation risk under a low noise regime as they traverse larger spatial extents. These effects are enhanced in large prey populations, which exhibit more ordered collective behavior or more uniform spatial distribution as they are interacting or independent, respectively.

Lin, Yuan; Abaid, Nicole

2013-12-01

133

Mechanisms of adaptation in a predator-prey arms race: TTX-resistant sodium channels.  

PubMed

Populations of the garter snake Thamnophis sirtalis have evolved geographically variable resistance to tetrodotoxin (TTX) in a coevolutionary arms race with their toxic prey, newts of the genus Taricha. Here, we identify a physiological mechanism, the expression of TTX-resistant sodium channels in skeletal muscle, responsible for adaptive diversification in whole-animal resistance. Both individual and population differences in the ability of skeletal muscle fibers to function in the presence of TTX correlate closely with whole-animal measures of TTX resistance. Demonstration of individual variation in an essential physiological function responsible for the adaptive differences among populations is a step toward linking the selective consequences of coevolutionary interactions to geographic and phylogenetic patterns of diversity. PMID:12193784

Geffeney, Shana; Brodie, Edmund D; Ruben, Peter C; Brodie, Edmund D

2002-08-23

134

Turing patterns and apparent competition in predator-prey food webs on networks  

NASA Astrophysics Data System (ADS)

Reaction-diffusion systems may lead to the formation of steady-state heterogeneous spatial patterns, known as Turing patterns. Their mathematical formulation is important for the study of pattern formation in general and plays central roles in many fields of biology, such as ecology and morphogenesis. Here we show that Turing patterns may have a decisive role in shaping the abundance distribution of predators and prey living in patchy landscapes. We extend the original model proposed by Nakao and Mikhailov [Nat. Phys.1745-247310.1038/nphys1651 6, 544 (2010)] by considering food chains with several interacting pairs of prey and predators distributed on a scale-free network of patches. We identify patterns of species distribution displaying high degrees of apparent competition driven by Turing instabilities. Our results provide further indication that differences in abundance distribution among patches can be generated dynamically by self organized Turing patterns and not only by intrinsic environmental heterogeneity.

Fernandes, L. D.; de Aguiar, M. A. M.

2012-11-01

135

Absorbing phase transition in a four-state predator-prey model in one dimension  

NASA Astrophysics Data System (ADS)

The model of competition between densities of two different species, called predator and prey, is studied on a one-dimensional periodic lattice, where each site can be in one of the four states, say, empty, or occupied by a single predator, or occupied by a single prey, or by both. Along with the pairwise death of predators and growth of prey, we introduce an interaction where the predators can eat one of the neighboring prey and reproduce a new predator there instantly. The model shows a non-equilibrium phase transition into an unusual absorbing state where predators are absent and the lattice is fully occupied by prey. The critical exponents of the system are found to be different from those of the directed percolation universality class and they are robust against addition of explicit diffusion.

Chatterjee, Rakesh; Mohanty, P. K.; Basu, Abhik

2011-05-01

136

Nonlinearities lead to qualitative differences in population dynamics of predator-prey systems.  

PubMed

Since typically there are many predators feeding on most herbivores in natural communities, understanding multiple predator effects is critical for both community and applied ecology. Experiments of multiple predator effects on prey populations are extremely demanding, as the number of treatments and the amount of labour associated with these experiments increases exponentially with the number of species in question. Therefore, researchers tend to vary only presence/absence of the species and use only one (supposedly realistic) combination of their numbers in experiments. However, nonlinearities in density dependence, functional responses, interactions between natural enemies etc. are typical for such systems, and nonlinear models of population dynamics generally predict qualitatively different results, if initial absolute densities of the species studied differ, even if their relative densities are maintained. Therefore, testing combinations of natural enemies without varying their densities may not be sufficient. Here we test this prediction experimentally. We show that the population dynamics of a system consisting of 2 natural enemies (aphid predator Adalia bipunctata (L.), and aphid parasitoid, Aphidius colemani Viereck) and their shared prey (peach aphid, Myzus persicae Sulzer) are strongly affected by the absolute initial densities of the species in question. Even if their relative densities are kept constant, the natural enemy species or combination thereof that most effectively suppresses the prey may depend on the absolute initial densities used in the experiment. Future empirical studies of multiple predator - one prey interactions should therefore use a two-dimensional array of initial densities of the studied species. Varying only combinations of natural enemies without varying their densities is not sufficient and can lead to misleading results. PMID:23638107

Ameixa, Olga M C C; Messelink, Gerben J; Kindlmann, Pavel

2013-01-01

137

Host plant quality, spatial heterogeneity, and the stability of mite predator-prey dynamics.  

PubMed

Population dynamics models suggest that both the over-all level of resource productivity and spatial variability in productivity can play important roles in community dynamics. Higher productivity environments are predicted to destabilize consumer-resource dynamics. Conversely, greater heterogeneity in resource productivity is expected to contribute to stability. Yet the importance of these two factors for the dynamics of arthropod communities has been largely overlooked. I manipulated nutrient availability for strawberry plants in a multi-patch experiment, and measured effects of overall plant quality and heterogeneity in plant quality on the stability of interactions between the phytophagous mite Tetranychus urticae and its predator Phytoseiulus persimilis. Plant size, leaf N content and T. urticae population growth increased monotonically with increasing soil nitrogen availability. This gradient in plant quality affected two correlates of mite population stability, population variability over time (i.e., coefficient of variation) and population persistence (i.e., proportion of plant patches colonized). However, the highest level of plant quality did not produce the least stable dynamics, which is inconsistent with the "paradox of enrichment". Heterogeneity in plant productivity had modest effects on stability, with the only significant difference being less variable T. urticae densities in the heterogeneous compared to the corresponding homogeneous treatment. These results are generally congruent with metapopulation theory and other models for spatially segregated populations, which predict that stability should be governed largely by relative movement rates of predators and prey--rather than patch quality. PMID:21053057

Daugherty, Matthew P

2011-04-01

138

Schoolyard Symbiosis.  

ERIC Educational Resources Information Center

Discusses different types of symbiosis--mutualism, commensalism, and parasitism--and examples of each type including lichens, legumes, mistletoe, and epiphytes. Describes how teachers can use these examples in the study of symbiosis which allows teachers to focus on many basic concepts in evolution, cell biology, ecology, and other fields of…

Allard, David W.

1996-01-01

139

Neo-Symbiosis: The Next Stage in the Evolution of Human Information Interaction.  

SciTech Connect

In his 1960 paper Man-Machine Symbiosis, Licklider predicted that human brains and computing machines will be coupled in a tight partnership that will think as no human brain has ever thought and process data in a way not approached by the information-handling machines we know today. Today we are on the threshold of resurrecting the vision of symbiosis. While Licklider’s original vision suggested a co-equal relationship, here we discuss an updated vision, neo-symbiosis, in which the human holds a superordinate position in an intelligent human-computer collaborative environment. This paper was originally published as a journal article and is being published as a chapter in an upcoming book series, Advances in Novel Approaches in Cognitive Informatics and Natural Intelligence.

Griffith, Douglas; Greitzer, Frank L.

2008-12-01

140

Neo-Symbiosis: The Next Stage in the Evolution of Human Information Interaction  

SciTech Connect

Abstract--The purpose of this paper is to re-address the vision of human-computer symbiosis as originally expressed by J.C.R. Licklider nearly a half-century ago. We describe this vision, place it in some historical context relating to the evolution of human factors research, and we observe that the field is now in the process of re-invigorating Licklider’s vision. We briefly assess the state of the technology within the context of contemporary theory and practice, and we describe what we regard as this emerging field of neo-symbiosis. We offer some initial thoughts on requirements to define functionality of neo-symbiotic systems and discuss research challenges associated with their development and evaluation.

Griffith, Douglas; Greitzer, Frank L.

2007-01-01

141

Man-Computer Symbiosis  

Microsoft Academic Search

Man-computer symbiosis is an expected development in cooperative interaction between men and electronic computers. It will involve very close coupling between the human and the electronic members of the partnership. The main aims are 1) to let computers facilitate formulative thinking as they now facilitate the solution of formulated problems, and 2) to enable men and computers to cooperate in

J. C. R. Licklider

1960-01-01

142

Quasi-soliton interaction of pursuit-evasion waves in a predator-prey system M. A. Tsyganov  

E-print Network

resulting from random motion of both species. We demonstrate a new type of propagating wave in this system Department of Applied Mathematics, University of Leeds, Leeds LS2 9JT, UK A. V. Holden School of Biomedical, including growth and inter- action of the species, and their undirected spread in space, e.g. resulting from

Biktashev, Vadim N.

143

Linking predator-prey interactions with exposure to a trophically transmitted parasite using PCR-based analyses.  

PubMed

Parasite transmission is determined by the rate of contact between a susceptible host and an infective stage and susceptibility to infection given an exposure event. Attempts to measure levels of variation in exposure in natural populations can be especially challenging. The level of exposure to a major class of parasites, trophically transmitted parasites, can be estimated by investigating the host's feeding behaviour. Since the parasites rely on the ingestion of infective intermediate hosts for transmission, the potential for exposure to infection is inherently linked to the definitive host's feeding ecology. Here, we combined epidemiological data and molecular analyses (polymerase chain reaction) of the diet of the definitive host, the white-footed mouse (Peromyscus leucopus), to investigate temporal and individual heterogeneities in exposure to infection. Our results show that the consumption of cricket intermediate hosts accounted for much of the variation in infection; mice that had consumed crickets were four times more likely to become infected than animals that tested negative for cricket DNA. In particular, pregnant female hosts were three times more likely to consume crickets, which corresponded to a threefold increase in infection compared with nonpregnant females. Interestingly, males in breeding condition had a higher rate of infection even though breeding males were just as likely to test positive for cricket consumption as nonbreeding males. These results suggest that while heterogeneity in host diet served as a strong predictor of exposure risk, differential susceptibility to infection may also play a key role, particularly among male hosts. By combining PCR analyses with epidemiological data, we revealed temporal variation in exposure through prey consumption and identified potentially important individual heterogeneities in parasite transmission. PMID:23110593

Luong, Lien T; Chapman, Eric G; Harwood, James D; Hudson, Peter J

2013-01-01

144

Teaching Symbiosis.  

ERIC Educational Resources Information Center

Argues that the meaning of the word "symbiosis" be standardized and that it should be used in a broad sense. Also criticizes the orthodox teaching of general principles in this subject and recommends that priority be given to continuity, intimacy, and associated adaptations, rather than to the harm/benefit relationship. (Author/JN)

Harper, G. H.

1985-01-01

145

Predator-prey relations between age-1+ summer flounder (Paralichthys dentatus, Linnaeus) and age-0 winter flounder (Pseudopleuronectes americanus, Walbaum): predator diets, prey selection, and effects of sediments and macrophytes.  

PubMed

Laboratory experiments and weekly trammel net surveys in the Navesink River, New Jersey (USA) were used to examine the predator-prey interaction between age-1+ summer flounder (Paralichthys dentatus) and age-0 winter flounder (Pseudopleuronectes americanus). Winter flounder (24-67 mm TL) were the dominant piscine prey of summer flounder (n=95, 252-648 mm TL) collected in trammel nets. We observed a temporal shift in summer flounder diets from sand shrimp (Crangon septemspinosa) and winter flounder, dominant during June and early July, to blue crabs (Callinectes sapidus) and other fishes (primarily Atlantic silversides, Menidia menidia and Atlantic menhaden, Brevortia tyrannus) later in the summer. Variations in prey selection appeared to be related to changes in the spatial distribution of predators and spatio-temporal variation in prey availability. In laboratory experiments, summer flounder (271-345 mm total length, TL) preferred demersal winter flounder to a pelagic fish (Atlantic silversides) and a benthic invertebrate (sand shrimp) prey, and the vulnerability of winter flounder increased with increasing prey body size from 20 to 90 mm TL. Experiments testing habitat effects showed that mortality of winter flounder in three different size classes (20-29, 40-49, 60-69 mm TL) was not influenced by sediment grain sizes permitting differential burial of the prey. However, vegetation enhanced survival, with fish suffering lower mortality in eelgrass (Zostera marina, 15+/-0.04%) than in sea lettuce (Ulva lactuca, 38+/-0.04%) or bare sand (70+/-0.07%) when the macrophytes were planted to produce similar leaf surface areas (5000 cm(2) m(-2)). Prey vulnerability appeared to be related to the role of vision in the predator's attack strategy and prey activity levels. PMID:10958899

Manderson; Phelan; Stoner; Hilbert

2000-08-23

146

Symbiosis: An Evolutionary Innovator.  

ERIC Educational Resources Information Center

Defines symbiosis and describes the connection between symbiosis and evolution, how it is described in science textbooks, and genetic variability. Discusses educational policy and science curriculum content. (YDS)

Case, Emily

2003-01-01

147

Neo-Symbiosis: The Next Stage in the Evolution of Human Information Interaction  

SciTech Connect

We re-address the vision of human-computer symbiosis expressed by J. C. R. Licklider nearly a half-century ago, when he wrote: “The hope is that in not too many years, human brains and computing machines will be coupled together very tightly, and that the resulting partnership will think as no human brain has ever thought and process data in a way not approached by the information-handling machines we know today.” (Licklider, 1960). Unfortunately, little progress was made toward this vision over four decades following Licklider’s challenge, despite significant advancements in the fields of human factors and computer science. Licklider’s vision was largely forgotten. However, recent advances in information science and technology, psychology, and neuroscience have rekindled the potential of making the Licklider’s vision a reality. This paper provides a historical context for and updates the vision, and it argues that such a vision is needed as a unifying framework for advancing IS&T.

Griffith, Douglas; Greitzer, Frank L.

2008-03-01

148

Pattern formation, long-term transients, and the Turing-Hopf bifurcation in a space- and time-discrete predator-prey system.  

PubMed

Understanding of population dynamics in a fragmented habitat is an issue of considerable importance. A natural modelling framework for these systems is spatially discrete. In this paper, we consider a predator-prey system that is discrete both in space and time, and is described by a Coupled Map Lattice (CML). The prey growth is assumed to be affected by a weak Allee effect and the predator dynamics includes intra-specific competition. We first reveal the bifurcation structure of the corresponding non-spatial system. We then obtain the conditions of diffusive instability on the lattice. In order to reveal the properties of the emerging patterns, we perform extensive numerical simulations. We pay a special attention to the system properties in a vicinity of the Turing-Hopf bifurcation, which is widely regarded as a mechanism of pattern formation and spatiotemporal chaos in space-continuous systems. Counter-intuitively, we obtain that the spatial patterns arising in the CML are more typically stationary, even when the local dynamics is oscillatory. We also obtain that, for some parameter values, the system's dynamics is dominated by long-term transients, so that the asymptotical stationary pattern arises as a sudden transition between two different patterns. Finally, we argue that our findings may have important ecological implications. PMID:20972714

Rodrigues, Luiz Alberto Díaz; Mistro, Diomar Cristina; Petrovskii, Sergei

2011-08-01

149

Effect of Predator-Prey Phylogenetic Similarity on the Fitness Consequences of Predation: A Trade-off between Nutrition and Disease?  

PubMed

A largely neglected aspect of foraging behavior is whether the costs and benefits of predation vary as a function of phylogenetic (i.e., genetic) similarity between predator and prey. Prey of varying phylogenetic similarities to predators might differ in value because both the risk of pathogen transmission and the nutritional quality of prey typically decline with decreasing phylogenetic similarity between predator and prey. I experimentally evaluated this hypothesis by feeding omnivorous spadefoot toad tadpoles (Spea bombifrons, Spea multiplicata, and Scaphiopus couchii) either conspecific tadpoles or an equal mass of three different species of heterospecific prey, all of which contained naturally occurring bacteria. I also examined which prey species Spea tadpoles preferred. I found that all three species of tadpoles performed best on, and preferred to eat, prey that were of intermediate phylogenetic similarity to the predators. Prey of intermediate phylogenetic similarity may provide the greatest fitness benefits to predators because such prey balance the nutritional benefits of closely related prey with the cost of parasite transmission between closely related individuals. PMID:10718730

Pfennig

2000-03-01

150

Symbiosis insights through metagenomic analysis of a microbial consortium  

E-print Network

ARTICLES Symbiosis insights through metagenomic analysis of a microbial consortium Tanja Woyke1 as it shuttles between the upper oxic and lower anoxic coastal sediments that it inhabits. Symbiosis has a major and interactions with the environment2 . This renaissance in symbiosis research stems from advances in molecular

Cai, Long

151

The detectability half-life in arthropod predator-prey research: what it is, why we need it, how to measure it, and how to use it.  

PubMed

Molecular gut-content analysis enables detection of arthropod predation with minimal disruption of ecosystem processes. Most assays produce only qualitative results, with each predator testing either positive or negative for target prey remains. Nevertheless, they have yielded important insights into community processes. For example, they have confirmed the long-hypothesized role of generalist predators in retarding early-season build-up of pest populations prior to the arrival of more specialized predators and parasitoids and documented the ubiquity of secondary and intraguild predation. However, raw qualitative gut-content data cannot be used to assess the relative impact of different predator taxa on prey population dynamics: they must first be weighted by the relative detectability periods for molecular prey remains for each predator-prey combination. If this is not carried out, interpretations of predator impact will be biased towards those with the longest detectabilities. We review the challenges in determining detectability half-lives, including unstated assumptions that have often been ignored in the performance of feeding trials. We also show how detectability half-lives can be used to properly weight assay data to rank predators by their importance in prey population suppression, and how sets of half-lives can be used to test hypotheses concerning predator ecology and physiology. We use data from 32 publications, comprising 97 half-lives, to generate and test hypotheses on taxonomic differences in detectability half-lives and discuss the possible role of the detectability half-life in interpreting qPCR and next-generation sequencing data. PMID:24303920

Greenstone, Matthew H; Payton, Mark E; Weber, Donald C; Simmons, Alvin M

2014-08-01

152

PredatorPrey Relationships 933 PredatorPrey  

E-print Network

and prey have shaped each other's behaviors, physiologies, morphologies, and life-history strategies-feeding bivalves; (16) sand dollars; (17) sea stars; (18) crabs; (19) bottom feeding fishes; (20) poly- chaetes; (21) predatory gastropods; and (22) deposit feeding bivalves. From McConnaughey and McRoy (1976). Sea

153

COMPLEX INTERACTIONS BETWEEN CLAPPER RAILS AND LAUGHING GULLS  

Microsoft Academic Search

HEN two species nest in the same habitat it is of interest to study their interactions, since ecological competition, predator-prey relationships and simple propinquity may lead to interspecific aggression. Clapper Rails (RaZZus Zongirostris) nest within a large colony of Laughing Gulls (Lams atricilh) in coastal Spartina marshes of the Brigantine National Wildlife Refuge north of Atlantic City, New Jersey. In

AMELIA SEGRI; JACK P. HAILMAN; C. G. BEER

154

Predatorprey coupling: interaction between mink Mustela vison and muskrat Ondatra zibethicus across Canada  

Microsoft Academic Search

In this paper we explore variation in the predator-prey interaction between mink Mustela vison and muskrat Ondatra zibethicus across Canada based on 25 years of mink (predator) and muskrat (prey) data from the Hudson's Bay Company. We show that predatorprey interactions have stronger signatures in the west of Canada than in the east. In particular, we show that the observed

Nina Holmengen; Knut Lehre Seip; Mark Boyce; Nils Chr

2008-01-01

155

Symbiosis specificity in the legume: rhizobial mutualism.  

PubMed

Legume plants are able to engage in root nodule symbiosis with nitrogen-fixing soil bacteria, collectively called rhizobia. This mutualistic association is highly specific, such that each rhizobial species/strain interacts with only a specific group of legumes, and vice versa. Symbiosis specificity can occur at multiple phases of the interaction, ranging from initial bacterial attachment and infection to late nodule development associated with nitrogen fixation. Genetic control of symbiosis specificity is complex, involving fine-tuned signal communication between the symbiotic partners. Here we review our current understanding of the mechanisms used by the host and bacteria to choose their symbiotic partners, with a special focus on the role that the host immunity plays in controlling the specificity of the legume - rhizobial symbiosis. PMID:22168434

Wang, Dong; Yang, Shengming; Tang, Fang; Zhu, Hongyan

2012-03-01

156

International Symbiosis Society  

NSDL National Science Digital Library

The International Symbiosis Society (ISS) "is primarily involved with the promotion of research and education in the growing field of symbiosis. The Society seeks also to build ongoing and useful communication between the many researchers working in the various sub-fields of symbiosis, as well as connect symbiologists to those in other areas of ecology and biological sciences generally." Hosted by Boston University, the ISS website contains information about membership, and the international journal _Symbiosis_. For authors interested in submitting a manuscript to the journal, the site provides brief, downloadable instructions. In addition, the site links to the websites of Society members working in a variety of areas including Bark Beetles/Fungi, Cyanobacterial Symbioses, Lichens, Marine Symbioses, Mycorhizae, and more. Also, be sure to check out the fascinating images in the Symbiosis Gallery! This site is also reviewed in the June 10, 2005 _NSDL Life Sciences Report_.

157

Computer symbiosis: Emergence of symbiotic behavior through evolution  

SciTech Connect

Symbiosis is altruistic cooperation between distinct species. It is one of the most effective evolutionary processes, but its dynamics are not well understood as yet. A simple model of symbiosis is introduced, where we consider interactions between hosts and parasites and also mutations of hosts and parasites. It is found that a symbiotic state emerges for a suitable range of mutation rates. The symbiotic state is not static, but dynamically oscillates. Harmful parasites violating symbiosis appear periodically, but are rapidly extinguished by hosts and other parasites, and the symbiotic state is recovered. The emergence of ''Tit for Tat'' strategy to maintain symbiosis is discussed. 4 figs.

Ikegami, Takashi; Kaneko, Kunihiko

1989-01-01

158

On Human Symbiosis and the Vicissitudes of Individuation. Infantile Psychosis, Volume 1.  

ERIC Educational Resources Information Center

The concepts of symbiosis and separation-individuation are explained, and the symbiosis theory of infantile psychosis is presented. Diagnostic considerations and clinical cases of child psychosis are reviewed; prototypes of mother-child interaction are described; and therapy is discussed. A summary of the symbiosis theory and a bibliography of…

Mahler, Margaret S.

159

Sensory ecology of predator–prey interactions: responses of the AN2 interneuron in the field cricket, Teleogryllus oceanicus to the echolocation calls of sympatric bats  

Microsoft Academic Search

We observed the responses of the AN2 interneuron in the Pacific field cricket, Teleogryllus oceanicus, a cell implicated in eliciting avoidance flight away from bats, to acoustic stimuli representing the echolocation calls of bats as well as field recordings of search and gleaning attack calls of six species of insectivorous sympatric bats (West Australia, Australia: Tadarida australis, Chalinolobus goudii, Nyctophilus

James H. Fullard; John M. Ratcliffe; Cassandra Guignion

2005-01-01

160

Aggressive mimicry, prey-specific predatory behaviour and predator-recognition in the predator-prey interactions of Portia fimbriata and Euryattus sp., jumping spiders from Queensland  

Microsoft Academic Search

Adults and large juveniles of Queensland Portia fimbriata, a salticid spider known to prey on other spiders (including other salticids), are shown to use prey-specific predatory behaviour against Euryattus sp., one of the salticids on which it feeds. Euryattus females are unusual because they nest inside suspended rolled-up leaves. P. fimbriata used vibratory displays to lure Euryattus females from their

Robert R. Jackson; R. Stimson Wilcox

1990-01-01

161

Predator–prey interaction in soil food web: functional response, size-dependent foraging efficiency, and the influence of soil texture  

Microsoft Academic Search

In a series of laboratory experiments, we presented carnivorous Macrobiotus richtersi (Tardigrada, Macrobiotidae) with nematode prey to assess their importance as predator. We investigated consumption rate for (a) different prey densities (10–400 prey individuals), (b) different prey biomasses (22–80 ng), (c) different prey species (Pelodera teres, Rhabditidae, versus Acrobeloides nanus, Cephalobidae) and (d) different environments (2-D agar surface versus 3-D sand

Karin Hohberg; Walter Traunspurger

2005-01-01

162

THE EFFECT OF SIZE ON THE FAST-START PERFORMANCE OF RAINBOW TROUT SALMO GAIRDNERI, AND A CONSIDERATION OF PISCIVOROUS PREDATOR-PREY INTERACTIONS  

Microsoft Academic Search

SUMMARY The fast-start (acceleration) performance of seven groups of rainbow trout from 9-6 to 387 cm total length was measured in response to d.c. electric shock stimuli. Two fast-start kinematic patterns, L- and S-start were observed. In L-starts the body was bent into an L or U shape and a recoil turn normally accompanied acceleration. Free manoeuvre was not possible

P. W. WEBB

163

Interactions in a tritrophic acarine predator-prey metapopulation system IV: effects of host plant condition on Tetranychus urticae (Acari: Tetranychidae)  

Microsoft Academic Search

Feeding by spider mites can cause severe injury to a host plant and lead to a decreasing per capita growth rate and an increasing per capita emigration rate. Such density-dependent responses to local conditions are important in a metapopulation context because they\\u000a allow the herbivores to colonize new host plants and thereby prolong the time until regional (metapopulation) extinction.\\u000a In

Gösta Nachman; Rostislav Zemek

2002-01-01

164

Interactions in a tritrophic acarine predator-prey metapopulation system III: Effects of Tetranychus urticae (Acari: Tetranychidae) on host plant condition  

Microsoft Academic Search

Spider mites are serious pests on many economically important plant species, because they may reduce plant productivity and,\\u000a at high mite densities, overexploit and even kill the host plants. We have conducted a series of greenhouse experiments to\\u000a quantify the effects of two-spotted spider mites (Tetranychus urticae) on host plants (Phaseolusvulgaris). The average amount of chlorophyll per cm2 leaf area

Gösta Nachman; Rostislav Zemek

2002-01-01

165

Effects of environmental conditions on predator–prey interactions between white sharks ( Carcharodon carcharias ) and Cape fur seals ( Arctocephalus pusillus pusillus ) at Seal Island, South Africa  

Microsoft Academic Search

Effects of environmental factors on frequency and success rate of 2,546 natural predatory attacks by white sharks, Carcharodon carcharias, on Cape fur seals, Arctocephalus pusillus pusillus, were studied over an 8-year period at Seal Island, South Africa. Attacks occurred primarily during winter months (June–August). Attack frequency increased significantly during northerly winds, during high tides, and within 400 m of the island,

Neil Hammerschlag; R. Aidan Martin; Chris Fallows

2006-01-01

166

Planet - Disk Symbiosis  

E-print Network

Planets form in disks around young stars. Interactions with these disks cause them to migrate and thus affect their final orbital periods. We suggest that the connection between planets and disks may be deeper and involve a symbiotic evolution. By contributing to the outward transport of angular momentum, planets promote disk accretion. Here we demonstrate that planets sufficiently massive to open gaps could be the primary agents driving disk accretion. Those having masses below the gap opening threshold drift inward more rapidly than the disk material and can only play a minor role in its accretion. Eccentricity growth during gap formation may involve an even more intimate symbiosis. Given a small initial eccentricity, just a fraction of a percent, the orbital eccentricity of a massive planet may grow rapidly once a mass in excess of the planet's mass has been repelled to form a gap around the planet's orbit. Then, as the planet's radial excursions approach the gap's width, subsequent eccentricity growth slows so that the planet's orbit continues to be confined within the gap.

Re'em Sari; Peter Goldreich

2003-07-05

167

The conflict interaction between two complex systems. Cyclic migration  

Microsoft Academic Search

We construct and study a discrete time model describing the conflict interaction between two complex systems with non-trivial internal structures. The external conflict interaction is based on the model of alternative interaction between a pair of non-annihilating opponents. The internal conflict dynamics is similar to the one of a predator-prey model. We show that the typical trajectory of the complex

S. Albeverio; V. Koshmanenko; I. Samoilenko

2009-01-01

168

Symbiosis: Rich, Exciting, Neglected Topic  

ERIC Educational Resources Information Center

Argues that the topic of symbiosis has been greatly neglected and underemphasized in general-biology textbooks. Discusses many types and examples of symbiosis, and provides an extensive bibliography of the literature related to this topic. (JR)

Rowland, Jane Thomas

1974-01-01

169

INDUSTRIAL SYMBIOSIS: Literature and Taxonomy  

Microsoft Academic Search

Abstract Industrial symbiosis, as part of the emerging field of industrial ecology, demands resolute attention to the flow of materials and energy through local and regional economies. Industrial symbiosis engages traditionally separate industries in a collective approach to competitive advantage involving physical exchange of materials, energy, water, and\\/or by-products. The keys to industrial symbiosis are collaboration and the synergistic possibilities

Marian R. Chertow

2000-01-01

170

Survival through Symbiosis.  

ERIC Educational Resources Information Center

Describes symbiosis and its significance in the day-to-day lives of plants and animals. Gives specific examples of mutualism, commensalism, and parasitism in the relationships among fungus and plant roots, animals and bacteria, birds and animals, fish, and predator and prey. (MDH)

Abdi, S. Wali

1992-01-01

171

Noise-guided evolution within cyclical interactions  

NASA Astrophysics Data System (ADS)

We study a stochastic predator prey model on a square lattice, where each of the six species has two superior and two inferior partners. The invasion probabilities between species depend on the predator prey pair and are supplemented by Gaussian noise. Conditions are identified that warrant the largest impact of noise on the evolutionary process, and the results of Monte Carlo simulations are qualitatively reproduced by a four-point cluster dynamical mean-field approximation. The observed noise-guided evolution is deeply routed in short-range spatial correlations, which is supported by simulations on other host lattice topologies. Our findings are conceptually related to the coherence resonance phenomenon in dynamical systems via the mechanism of threshold duality. We also show that the introduced concept of noise-guided evolution via the exploitation of threshold duality is not limited to predator prey cyclical interactions, but may apply to models of evolutionary game theory as well, thus indicating its applicability in several different fields of research.

Perc, Matjaž; Szolnoki, Attila

2007-08-01

172

Interactions between the leech Glossiphonia complanata and its gastropod prey  

Microsoft Academic Search

Predator-prey interactions between the predatory leech, Glossiphonia complanata, and its gastropod prey were investigated in laboratory experiments, including behavioural observations with the aid of time-lapse video technique. Six gastropod species were investigated, viz. Lymnaea peregra, Planorbis planorbis, Physa fontinalis, Ancylus fluviatilis, Bithynia tentaculata, and Theodoxus fluviatilis. The species studied exhibited anti-predator defences, which had their maximum efficiency at different stages

Christer Briinmark; Bjiirn Malmqvist

1986-01-01

173

MTH 480: Systems of Ordinary Differential Equations Mathematical Models in Ecology  

E-print Network

, competition between species and predator prey relationships, among others. We will mainly focus on systems for Interacting Species, Kolmogorov models and classification into Predator- Prey, Competition and Mutualistic

Bokil, Vrushali

174

Molecular diagnosis of a previously unreported predator–prey association in coffee: Karnyothrips flavipes Jones (Thysanoptera: Phlaeothripidae) predation on the coffee berry borer  

Microsoft Academic Search

The coffee berry borer, Hypothenemus hampei, is the most important pest of coffee throughout the world, causing losses estimated at US $500 million\\/year. The thrips Karnyothrips flavipes was observed for the first time feeding on immature stages of H. hampei in April 2008 from samples collected in the Kisii area of Western Kenya. Since the trophic interactions between H. hampei

Juliana Jaramillo; Eric G. Chapman; Fernando E. Vega; James D. Harwood

2010-01-01

175

Symbiosis Teaching Workshop -5th International Symbiosis Society Congress, Vienna, August 4-10, 2006 LAB ACTIVITY  

E-print Network

Symbiosis Teaching Workshop - 5th International Symbiosis Society Congress, Vienna, August 4-10, 2006 LAB ACTIVITY FOR SYMBIOSIS TEACHING DISCOVERING AZOLLA;Symbiosis Teaching Workshop - 5th International Symbiosis Society Congress, Vienna

Carrapiço, Francisco

176

Molecular diagnosis of a previously unreported predator-prey association in coffee: Karnyothrips flavipes Jones (Thysanoptera: Phlaeothripidae) predation on the coffee berry borer  

NASA Astrophysics Data System (ADS)

The coffee berry borer, Hypothenemus hampei, is the most important pest of coffee throughout the world, causing losses estimated at US 500 million/year. The thrips Karnyothrips flavipes was observed for the first time feeding on immature stages of H. hampei in April 2008 from samples collected in the Kisii area of Western Kenya. Since the trophic interactions between H. hampei and K. flavipes are carried out entirely within the coffee berry, and because thrips feed by liquid ingestion, we used molecular gut-content analysis to confirm the potential role of K. flavipes as a predator of H. hampei in an organic coffee production system. Species-specific COI primers designed for H. hampei were shown to have a high degree of specificity for H. hampei DNA and did not produce any PCR product from DNA templates of the other insects associated with the coffee agroecosystems. In total, 3,327 K. flavipes emerged from 17,792 H. hampei-infested berries collected from the field between April and September 2008. Throughout the season, 8.3% of K. flavipes tested positive for H. hampei DNA, although at times this figure approached 50%. Prey availability was significantly correlated with prey consumption, thus indicating the potential impact on H. hampei populations.

Jaramillo, Juliana; Chapman, Eric G.; Vega, Fernando E.; Harwood, James D.

2010-03-01

177

Modelling Ammonium Transporters in Arbuscular Mycorrhiza Symbiosis  

E-print Network

Modelling Ammonium Transporters in Arbuscular Mycorrhiza Symbiosis Mario Coppo1 , Ferruccio Damiani, the most wide-spread plant-fungus symbiosis on earth. Inves- tigating this kind of symbiosis is considered), the most widespread symbiosis between plants and fungi, got into the focus of research because of its

Troina, Angelo

178

Symbiosis of Thioautotrophic Bacteria with Riftia Introduction  

E-print Network

1 Symbiosis of Thioautotrophic Bacteria with Riftia pachyptila Introduction The symbiosis between-rich hydrothermal vents. In the decade following the initial description of this symbiosis in 1981 (Cavanaugh et al of chemosynthetic symbioses. Specifically, for the R. pachyptila symbiosis, researchers provided new insights

Stewart, Frank

179

Interactions between cougars (Puma concolor) and gray wolves (Canis lupus) in Banff National Park, Alberta  

Microsoft Academic Search

Large carnivore populations are recovering in many protected areas in North America, but the effect of increasing carnivore numbers on existing predator-prey and predator-predator interactions is poorly understood. We studied diet and spatial overlap among cougars (Puma concolor) and gray wolves (Canis lupus) in Banff National Park, Alberta (1993-2004) to evaluate how wolf recovery in the park influenced diet choice

Andrea D. KORTELLO; Thomas E. HURD; Dennis L. MURRAY

2007-01-01

180

Crab: snail size-structured interactions and salt marsh predation gradients  

Microsoft Academic Search

We studied size-structured predator-prey interactions between blue crabs (Callinectes sapidus) and marsh periwinkles (Littoraria irrorata) with a combination of field studies, laboratory experiments and individual-based modeling. Size distributions of Littoraria differed among years at the same sites in a salt marsh and could largely be explained by dominance of strong cohorts in the population. At a given site, abundance increased

Daniel E. Schindler; Brett M. Johnson; Neil A. MacKay; Nicolaas Bouwes; James F. Kitchell

1994-01-01

181

MANAGEMENT OF THE PREDATOR PREY RELATIONSHIP  

E-print Network

in 1912 · No AWPE colony on Gull Island prior to that date · Predator removal from Gull Island in 1991 · Intense YCT fishery (humans) in the 1950's to early 80's resulted in overexploitationand collapse · Catch-8 kmto mouth of river 1 km= gauntlet Gull& Willow Island AWPE Colony 57 km to confluence STUDY AREA 0 500

182

Predation: Prey plumage adaptation against falcon attack.  

PubMed

Several plumage types are found in feral pigeons (Columba livia), but one type imparts a clear survival advantage during attacks by the swiftest of all predators--the peregrine falcon (Falco peregrinus). Here we use quantitative field observations and experiments to demonstrate both the selective nature of the falcon's choice of prey and the effect of plumage coloration on the survival of feral pigeons. This plumage colour is an independently heritable trait that is likely to be an antipredator adaptation against high-speed attacks in open air space. PMID:15846334

Palleroni, Alberto; Miller, Cory T; Hauser, Marc; Marler, Peter

2005-04-21

183

Predators & Prey BIO3176 -University of Ottawa  

E-print Network

J Lin Soc 30: 31-44 16 · Great tits (Parus major), twigs (twine in opaque straw), big worms in opaque straw, and small worms in clear straw · Twigs are not edible · Big worms are cryptic · Small worms are conspicuous Advantage twigs = 4 x big worms opposite 0% 20% 40% 60% 80% A B conspicuous prey taken Erichsen et

Blouin-Demers, Gabriel

184

Ectomycorrhizal symbiosis enhanced the efficiency of inoculation with two Bradyrhizobium strains and Acacia holosericea growth  

Microsoft Academic Search

Two strains of Bradyrhizobium sp., Aust 13C and Aust 11C, were dually or singly inoculated with an ectomycorrhizal fungus, Pisolithus albus to assess the interactions between ectomycorrhizal symbiosis and the nodulation process in glasshouse conditions. Sequencing of strains Aust 13C and Aust 11C confirmed their previous placement in the genus Bradyrhizobium. After 4 months’ culture, the ectomycorrhizal symbiosis promoted plant

S. André; A. Galiana; C. Le Roux; Y Prin; M. Neyra; R. Duponnois

2005-01-01

185

Topic 3: Toward Understanding the Role of Diet in Host–Parasite Interactions: The Case for Japanese Macaques  

Microsoft Academic Search

\\u000a Central to understanding animal ecology are interactions between consumers and the consumed, whether predator–prey, herbivore–plant,\\u000a or mycophage–mushroom. A wealth of information exists describing just such relationships (Stephens and Krebs 1986; Stephens\\u000a et al. 2007). The first systematic and naturalistic study of primates (Alouatta palliata: Carpenter 1934) reported a partial list of items consumed by howler monkeys. Since then, countless food

Andrew J. J. MacIntosh; Michael A. Huffman

186

Expanding genomics of mycorrhizal symbiosis  

PubMed Central

The mycorrhizal symbiosis between soil fungi and plant roots is a ubiquitous mutualism that plays key roles in plant nutrition, soil health, and carbon cycling. The symbiosis evolved repeatedly and independently as multiple morphotypes [e.g., arbuscular mycorrhizae (AM), ectomycorrhizal (ECM)] in multiple fungal clades (e.g., phyla Glomeromycota, Ascomycota, Basidiomycota). The accessibility and cultivability of many mycorrhizal partners make them ideal models for symbiosis studies. Alongside molecular, physiological, and ecological investigations, sequencing led to the first three mycorrhizal fungal genomes, representing two morphotypes and three phyla. The genome of the ECM basidiomycete Laccaria bicolor showed that the mycorrhizal lifestyle can evolve through loss of plant cell wall-degrading enzymes (PCWDEs) and expansion of lineage-specific gene families such as short secreted protein (SSP) effectors. The genome of the ECM ascomycete Tuber melanosporum showed that the ECM type can evolve without expansion of families as in Laccaria, and thus a different set of symbiosis genes. The genome of the AM glomeromycete Rhizophagus irregularis showed that despite enormous phylogenetic distance and morphological difference from the other two fungi, symbiosis can involve similar solutions as symbiosis-induced SSPs and loss of PCWDEs. The three genomes provide a solid base for addressing fundamental questions about the nature and role of a vital mutualism. PMID:25408690

Kuo, Alan; Kohler, Annegret; Martin, Francis M.; Grigoriev, Igor V.

2014-01-01

187

Symbiosis catalyses niche expansion and diversification  

PubMed Central

Interactions between species are important catalysts of the evolutionary processes that generate the remarkable diversity of life. Symbioses, conspicuous and inherently interesting forms of species interaction, are pervasive throughout the tree of life. However, nearly all studies of the impact of species interactions on diversification have concentrated on competition and predation leaving unclear the importance of symbiotic interaction. Here, I show that, as predicted by evolutionary theories of symbiosis and diversification, multiple origins of a key innovation, symbiosis between gall-inducing insects and fungi, catalysed both expansion in resource use (niche expansion) and diversification. Symbiotic lineages have undergone a more than sevenfold expansion in the range of host-plant taxa they use relative to lineages without such fungal symbionts, as defined by the genetic distance between host plants. Furthermore, symbiotic gall-inducing insects are more than 17 times as diverse as their non-symbiotic relatives. These results demonstrate that the evolution of symbiotic interaction leads to niche expansion, which in turn catalyses diversification. PMID:23390106

Joy, Jeffrey B.

2013-01-01

188

Frankia-actinorhizal plant symbiosis Actinorhizal plants form root nodules in symbiosis with the nitrogen-fixing actinomycete  

E-print Network

Frankia-actinorhizal plant symbiosis Actinorhizal plants form root nodules in symbiosis themselves. The establishment and efficiency of the symbiosis between Frankia and actinorhizal plants constrained by the genotypes of both partners of this symbiosis. Effects of environmental conditions, plant

Aspbury, Andrea S. - Department of Biology, Texas State University

189

Evolving together: the biology of symbiosis, part 1  

PubMed Central

Symbioses, prolonged associations between organisms often widely separated phylogenetically, are more common in biology than we once thought and have been neglected as a phenomenon worthy of study on its own merits. Extending along a dynamic continuum from antagonistic to cooperative and often involving elements of both antagonism and mutualism, symbioses involve pathogens, commensals, and mutualists interacting in myriad ways over the evolutionary history of the involved “partners.” In this first of 2 parts, some remarkable examples of symbiosis will be explored, from the coral-algal symbiosis and nitrogen fixation to the great diversity of dietary specializations enabled by the gastrointestinal microbiota of animals. PMID:16389385

2000-01-01

190

Symbiosis, Empathy, Suicidal Behavior, and the Family.  

ERIC Educational Resources Information Center

This paper discusses the theoretical concept of symbiosis, as described by Mahler and her co-workers, and its clinical applications in suicidal situations. Also, the practical implications of the concept of symbiosis for assessment and treatment are discussed (Author)

Richman, Joseph

1978-01-01

191

Interorganismal signaling in suboptimum environments: The legume-rhizobia symbiosis  

Microsoft Academic Search

During the Rhizobium-legume interactions that lead to the establishment of the nitrogen fixing symbiosis, an exchange of molecular signals regulates the expression of genes essential for infection, nodule development, and function. All stages of nodule formation and function are impacted by stressful environmental conditions and by soil nitrogen levels. Researchers have concluded that these conditions decrease N2fixation activity by directly

F Zhang; D. L Smith

2002-01-01

192

ORIGINAL ARTICLE A novel symbiosis between  

E-print Network

ORIGINAL ARTICLE A novel symbiosis between chemoautotrophic bacteria and a freshwater cave amphipod the first known example of a non-marine chemoautotroph-animal symbiosis. Conditions supporting 000 and 1 million years ago. Therefore, the N. ictus-Thiothrix symbiosis is probably significantly

Macalady, Jenn

193

SYMBIOSIS POINTS FOR LINEAR DIFFERENTIAL SYSTEMS  

E-print Network

SYMBIOSIS POINTS FOR LINEAR DIFFERENTIAL SYSTEMS Michael Neumann and Michael J. Tsatsomeros the notion of a symbiosis point for the system. This is a point in XA(Rn +) such that also the velocity become and remain nondecreasing. We characterize all symbiosis points for the system. We also show

Tsatsomeros, Michael

194

Symbiosis Workshop 2011 Symposium Schedule  

E-print Network

and its relationship to pine seedling establishment. · 4:40 Closing remarks (Monica- and endo-symbiotic bacteria and archaea in rumen protists · 10:50-11:10 AM M. Pilar Francino Host-microbial symbiosis in the human gastrointestinal tract

Sachs, Joel

195

ANNUAL SYMBIOSIS WORKSHOP ---MAY 19-20TH , 2012  

E-print Network

2ND ANNUAL SYMBIOSIS WORKSHOP --- MAY 19-20TH , 2012 SYMBIOSIS WORKSHOP 2012 PRELIMINARY SYMPOSIUM SCHEDULE SIERRA NEVADA RESEARCH INSTITUTE HTTP://WWW.SACHSLAB.COM/SYMBIOSIS-WORKSHOP-2012.PHP ORGANIZED BY JOEL L. SACHS

Sachs, Joel

196

SYMBIOSIS: COOPERATIVE ALGORITHMS FOR MOBILE ROBOTS AND A SENSOR NETWORK  

E-print Network

SYMBIOSIS: COOPERATIVE ALGORITHMS FOR MOBILE ROBOTS AND A SENSOR NETWORK by Maxim Alexander Batalin - Symbiosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1.3 Problem Description and Thesis

Southern California, University of

197

Evolution of symbiosis with resource allocation from fecundity to survival.  

PubMed

Symbiosis is one of the most fundamental relationships between or among organisms and includes parasitism (which has negative effects on the fitness of the interacting partner), commensalism (no effect), and mutualism (positive effects). The effects of these interactions are usually assumed to influence a single component of a species' fitness, either survival or fecundity, even though in reality the interaction can simultaneously affect both of these components. I used a dual lattice model to investigate the process of evolution of mutualistic symbiosis in the presence of interactive effects on both survival and fecundity. I demonstrate that a positive effect on survival and a negative effect on fecundity are key to the establishment of mutualism. Furthermore, both the parasitic and the mutualistic behaviour must carry large costs for mutualism to evolve. This helps develop a new understanding of symbiosis as a function of resource allocation, in which resources are shifted from fecundity to survival. The simultaneous establishment of mutualism from parasitism never occurs in two species, but can do so in one of the species as long as the partner still behaves parasitically. This suggests that one of the altruistic behaviours in a mutualistic unit consisting of two species must originate as a parasitic behaviour. PMID:24744057

Fukui, Shin

2014-05-01

198

Cell Biology of Cnidarian-Dinoflagellate Symbiosis  

PubMed Central

Summary: The symbiosis between cnidarians (e.g., corals or sea anemones) and intracellular dinoflagellate algae of the genus Symbiodinium is of immense ecological importance. In particular, this symbiosis promotes the growth and survival of reef corals in nutrient-poor tropical waters; indeed, coral reefs could not exist without this symbiosis. However, our fundamental understanding of the cnidarian-dinoflagellate symbiosis and of its links to coral calcification remains poor. Here we review what we currently know about the cell biology of cnidarian-dinoflagellate symbiosis. In doing so, we aim to refocus attention on fundamental cellular aspects that have been somewhat neglected since the early to mid-1980s, when a more ecological approach began to dominate. We review the four major processes that we believe underlie the various phases of establishment and persistence in the cnidarian/coral-dinoflagellate symbiosis: (i) recognition and phagocytosis, (ii) regulation of host-symbiont biomass, (iii) metabolic exchange and nutrient trafficking, and (iv) calcification. Where appropriate, we draw upon examples from a range of cnidarian-alga symbioses, including the symbiosis between green Hydra and its intracellular chlorophyte symbiont, which has considerable potential to inform our understanding of the cnidarian-dinoflagellate symbiosis. Ultimately, we provide a comprehensive overview of the history of the field, its current status, and where it should be going in the future. PMID:22688813

Allemand, Denis; Weis, Virginia M.

2012-01-01

199

Brain-Computer Symbiosis  

PubMed Central

The theoretical groundwork of the 1930’s and 1940’s and the technical advance of computers in the following decades provided the basis for dramatic increases in human efficiency. While computers continue to evolve, and we can still expect increasing benefits from their use, the interface between humans and computers has begun to present a serious impediment to full realization of the potential payoff. This article is about the theoretical and practical possibility that direct communication between the brain and the computer can be used to overcome this impediment by improving or augmenting conventional forms of human communication. It is about the opportunity that the limitations of our body’s input and output capacities can be overcome using direct interaction with the brain, and it discusses the assumptions, possible limitations, and implications of a technology that I anticipate will be a major source of pervasive changes in the coming decades. PMID:18310804

Schalk, Gerwin

2009-01-01

200

Sensory Information and Encounter Rates of Interacting Species  

PubMed Central

Most motile organisms use sensory cues when searching for resources, mates, or prey. The searcher measures sensory data and adjusts its search behavior based on those data. Yet, classical models of species encounter rates assume that searchers move independently of their targets. This assumption leads to the familiar mass action-like encounter rate kinetics typically used in modeling species interactions. Here we show that this common approach can mischaracterize encounter rate kinetics if searchers use sensory information to search actively for targets. We use the example of predator-prey interactions to illustrate that predators capable of long-distance directional sensing can encounter prey at a rate proportional to prey density to the power (where is the dimension of the environment) when prey density is low. Similar anomalous encounter rate functions emerge even when predators pursue prey using only noisy, directionless signals. Thus, in both the high-information extreme of long-distance directional sensing, and the low-information extreme of noisy non-directional sensing, encounter rate kinetics differ qualitatively from those derived by classic theory of species interactions. Using a standard model of predator-prey population dynamics, we show that the new encounter rate kinetics derived here can change the outcome of species interactions. Our results demonstrate how the use of sensory information can alter the rates and outcomes of physical interactions in biological systems. PMID:23966847

Hein, Andrew M.; McKinley, Scott A.

2013-01-01

201

Phosphorus and Nitrogen Regulate Arbuscular Mycorrhizal Symbiosis in Petunia hybrida  

PubMed Central

Phosphorus and nitrogen are essential nutrient elements that are needed by plants in large amounts. The arbuscular mycorrhizal symbiosis between plants and soil fungi improves phosphorus and nitrogen acquisition under limiting conditions. On the other hand, these nutrients influence root colonization by mycorrhizal fungi and symbiotic functioning. This represents a feedback mechanism that allows plants to control the fungal symbiont depending on nutrient requirements and supply. Elevated phosphorus supply has previously been shown to exert strong inhibition of arbuscular mycorrhizal development. Here, we address to what extent inhibition by phosphorus is influenced by other nutritional pathways in the interaction between Petunia hybrida and R. irregularis. We show that phosphorus and nitrogen are the major nutritional determinants of the interaction. Interestingly, the symbiosis-promoting effect of nitrogen starvation dominantly overruled the suppressive effect of high phosphorus nutrition onto arbuscular mycorrhiza, suggesting that plants promote the symbiosis as long as they are limited by one of the two major nutrients. Our results also show that in a given pair of symbiotic partners (Petunia hybrida and R. irregularis), the entire range from mutually symbiotic to parasitic can be observed depending on the nutritional conditions. Taken together, these results reveal complex nutritional feedback mechanisms in the control of root colonization by arbuscular mycorrhizal fungi. PMID:24608923

Nouri, Eva; Breuillin-Sessoms, Florence; Feller, Urs; Reinhardt, Didier

2014-01-01

202

PtSRR1, a putative Pisolithus tinctorius symbiosis related receptor gene is expressed during the first hours of mycorrhizal interaction with Castanea sativa roots.  

PubMed

PtSRR1 EST was previously identified in the first hours of Pisolithus tinctorius and Castanea sativa interaction. QRT-PCR confirmed PtSRR1 early expression and in silico preliminary translated peptide analysis indicated a strong probability that PtSRR1 be a transmembrane protein. These data stimulate the PtSRR1 gene research during ectomycorrhiza formation. PMID:24031360

Acioli-Santos, B; Malosso, E; Calzavara-Silva, C E; Lima, C E P; Figueiredo, A; Sebastiana, M; Pais, M S

2009-04-01

203

Friend or foe? A behavioral and stable isotopic investigation of an ant–plant symbiosis  

Microsoft Academic Search

In ant–plant symbioses, the behavior of ant inhabitants affects the nature of the interaction, ranging from mutualism to parasitism. Mutualistic species confer a benefit to the plant, while parasites reap the benefits of the interaction without reciprocating, potentially resulting in a negative impact on the host plant. Using the ant–plant symbiosis between Cordia alliodora and its ant inhabitants as a

Chadwick V. Tillberg

2004-01-01

204

Amazing Reef: Moviemaker  

NSDL National Science Digital Library

In this movie-making interactive, learners can make an animated film about life on a coral reef. Learners choose an exciting story, cast colorful characters, and animate the movie themselves. They then add music and titles to complete the movie. Learners can even keep the movie by downloading it to their own computer. Learners can make up to four movies relating to survival, symbiosis, habitat, and predator/prey relationships in the Philippines Tropical Coral Reef.

Aquarium, Shedd; Educational Web Adventures (Eduweb)

2006-01-01

205

Symbiosis.  

ERIC Educational Resources Information Center

Exposing today's students to a balance of science and the outside world is critical. The outdoors provides a context for practical applications of science, exposing the relevance of science to everyday life. Outdoor education instills an awareness that the health of the environment is directly coupled with our own health, enabling us to make…

Bicevskis, Rob

2002-01-01

206

Consequences of symbiosis for food web dynamics.  

PubMed

Basic Lotka-Volterra type models in which mutualism (a type of symbiosis where the two populations benefit both) is taken into account, may give unbounded solutions. We exclude such behaviour using explicit mass balances and study the consequences of symbiosis for the long-term dynamic behaviour of a three species system, two prey and one predator species in the chemostat. We compose a theoretical food web where a predator feeds on two prey species that have a symbiotic relationships. In addition to a species-specific resource, the two prey populations consume the products of the partner population as well. In turn, a common predator forages on these prey populations. The temporal change in the biomass and the nutrient densities in the reactor is described by ordinary differential equations (ODE). Since products are recycled, the dynamics of these abiotic materials must be taken into account as well, and they are described by odes in a similar way as the abiotic nutrients. We use numerical bifurcation analysis to assess the long-term dynamic behaviour for varying degrees of symbiosis. Attractors can be equilibria, limit cycles and chaotic attractors depending on the control parameters of the chemostat reactor. These control parameters that can be experimentally manipulated are the nutrient density of the inflow medium and the dilution rate. Bifurcation diagrams for the three species web with a facultative symbiotic association between the two prey populations, are similar to that of a bi-trophic food chain; nutrient enrichment leads to oscillatory behaviour. Predation combined with obligatory symbiotic prey-interactions has a stabilizing effect, that is, there is stable coexistence in a larger part of the parameter space than for a bi-trophic food chain. However, combined with a large growth rate of the predator, the food web can persist only in a relatively small region of the parameter space. Then, two zero-pair bifurcation points are the organizing centers. In each of these points, in addition to a tangent, transcritical and Hopf bifurcation a global heteroclinic bifurcation is emanating. This heteroclinic cycle connects two saddle equilibria where the predator is absent. Under parameter variation the period of the stable limit cycle goes to infinity and the cycle tends to the heteroclinic cycle. At this global bifurcation point this cycle breaks and the boundary of the basin of attraction disappears abruptly because the separatrix disappears together with the cycle. As a result, it becomes possible that a stable two-nutrient-two-prey population system becomes unstable by invasion of a predator and eventually the predator goes extinct together with the two prey populations, that is, the complete food web is destroyed. This is a form of over-exploitation by the predator population of the two symbiotic prey populations. When obligatory symbiotic prey-interactions are modelled with Liebig's minimum law, where growth is limited by the most limiting resource, more complicated types of bifurcations are found. This results from the fact that the Jacobian matrix changes discontinuously with respect to a varying parameter when another resource becomes most limiting. PMID:15293013

Kooi, B W; Kuijper, L D J; Kooijman, S A L M

2004-09-01

207

Ammonium Metabolism in the Green Hydra Symbiosis  

Microsoft Academic Search

Abstract. Inhibitors of enzymes,of ammonium,assimi- lation were used to test if assimilation of ammonium,in the green,hydra-Chlorella symbiosis,was,due,to host or symbionts. Both methionine sulphoximine (MSX, an in- hibitor of glutamine synthetase, found in both host and symbionts) and azaserine (AZS, an inhibitor of 2-oxoglu- tarate amido transferase, not found in the host) inhibited ammonium,uptake by the intact symbiosis. MSX was taken

P. J. Mcauley

1995-01-01

208

Persistence in fluctuating environments for interacting structured populations.  

PubMed

Individuals within any species exhibit differences in size, developmental state, or spatial location. These differences coupled with environmental fluctuations in demographic rates can have subtle effects on population persistence and species coexistence. To understand these effects, we provide a general theory for coexistence of structured, interacting species living in a stochastic environment. The theory is applicable to nonlinear, multi species matrix models with stochastically varying parameters. The theory relies on long-term growth rates of species corresponding to the dominant Lyapunov exponents of random matrix products. Our coexistence criterion requires that a convex combination of these long-term growth rates is positive with probability one whenever one or more species are at low density. When this condition holds, the community is stochastically persistent: the fraction of time that a species density goes below [Formula: see text] approaches zero as [Formula: see text] approaches zero. Applications to predator-prey interactions in an autocorrelated environment, a stochastic LPA model, and spatial lottery models are provided. These applications demonstrate that positive autocorrelations in temporal fluctuations can disrupt predator-prey coexistence, fluctuations in log-fecundity can facilitate persistence in structured populations, and long-lived, relatively sedentary competing populations are likely to coexist in spatially and temporally heterogenous environments. PMID:24311028

Roth, Gregory; Schreiber, Sebastian J

2014-11-01

209

Sustainable agriculture: possible trajectories from mutualistic symbiosis and plant neodomestication  

E-print Network

Sustainable agriculture: possible trajectories from mutualistic symbiosis and plant. Based on recent findings, new trajectories for agriculture and plant breeding which take into account symbiosis in an innovative ecologically intensive agriculture. A sustainable food production ? Feeding

Paris-Sud XI, Université de

210

Search Engine-Crawler Symbiosis: Adapting to Community Interests  

E-print Network

Search Engine-Crawler Symbiosis: Adapting to Community Interests Gautam Pant, Shannon Bradshaw the crawler to better its performance. We show that the symbiosis can help the system learn about a community

Bradshaw, Shannon

211

The Bifunctional Plant Receptor, OsCERK1, Regulates Both Chitin-Triggered Immunity and Arbuscular Mycorrhizal Symbiosis in Rice.  

PubMed

Plants are constantly exposed to threats from pathogenic microbes and thus developed an innate immune system to protect themselves. On the other hand, many plants also have the ability to establish endosymbiosis with beneficial microbes such as arbuscular mycorrhizal (AM) fungi or rhizobial bacteria, which improves the growth of host plants. How plants evolved these systems managing such opposite plant-microbe interactions is unclear. We show here that knockout (KO) mutants of OsCERK1, a rice receptor kinase essential for chitin signaling, were impaired not only for chitin-triggered defense responses but also for AM symbiosis, indicating the bifunctionality of OsCERK1 in defense and symbiosis. On the other hand, a KO mutant of OsCEBiP, which forms a receptor complex with OsCERK1 and is essential for chitin-triggered immunity, established mycorrhizal symbiosis normally. Therefore, OsCERK1 but not chitin-triggered immunity is required for AM symbiosis. Furthermore, experiments with chimeric receptors showed that the kinase domains of OsCERK1 and homologs from non-leguminous, mycorrhizal plants could trigger nodulation signaling in legume-rhizobium interactions as the kinase domain of Nod factor receptor1 (NFR1), which is essential for triggering the nodulation program in leguminous plants, did. Because leguminous plants are believed to have developed the rhizobial symbiosis on the basis of AM symbiosis, our results suggest that the symbiotic function of ancestral CERK1 in AM symbiosis enabled the molecular evolution to leguminous NFR1 and resulted in the establishment of legume-rhizobia symbiosis. These results also suggest that OsCERK1 and homologs serve as a molecular switch that activates defense or symbiotic responses depending on the infecting microbes. PMID:25231970

Miyata, Kana; Kozaki, Toshinori; Kouzai, Yusuke; Ozawa, Kenjirou; Ishii, Kazuo; Asamizu, Erika; Okabe, Yoshihiro; Umehara, Yosuke; Miyamoto, Ayano; Kobae, Yoshihiro; Akiyama, Kohki; Kaku, Hanae; Nishizawa, Yoko; Shibuya, Naoto; Nakagawa, Tomomi

2014-11-01

212

Symbiosis through exploitation and the merger of lineages in evolution  

E-print Network

Symbiosis through exploitation and the merger of lineages in evolution Richard Law1* and Ulf for the coevolution of two species in facultative symbiosis is used to investigate conditions under which species of resources from an individual to its partner, and the second a¡ecting vertical transmission of the symbiosis

Dieckmann, Ulf

213

ORIGINAL PAPER Onset of symbiosis and distribution patterns of symbiotic  

E-print Network

ORIGINAL PAPER Onset of symbiosis and distribution patterns of symbiotic dinoflagellates Springer-Verlag 2009 Abstract The establishment of symbiosis in early developmental stages is important and detailed process of the onset of symbiosis. We examined larval uptake of symbiotic dino- flagellates

214

Evolutionary transitions in bacterial symbiosis Joel L. Sachs1  

E-print Network

Evolutionary transitions in bacterial symbiosis Joel L. Sachs1 , Ryan G. Skophammer, and John U mutualism. Each of these transitions has occurred many times in the history of bacterial­eukaryote symbiosis evolutionary transitions in bacterial symbiosis and test hypotheses about the selective, ecological

Sachs, Joel

215

The genome of Laccaria bicolor provides insights into mycorrhizal symbiosis  

E-print Network

LETTERS The genome of Laccaria bicolor provides insights into mycorrhizal symbiosis F. Martin1 , A and physiology, allowing the full ecological significance of this symbiosis to be explored. Here we report involved in rhizosphere colonization and symbiosis. This 65-megabase gen- ome assembly contains 20

Bruns, Tom

216

Probabilistic Modeling for Job Symbiosis Scheduling on SMT Processors  

E-print Network

7 Probabilistic Modeling for Job Symbiosis Scheduling on SMT Processors STIJN EYERMAN and LIEVEN system-level priorities/shares. This article proposes probabilistic job symbiosis modeling, which predicts whether jobs will create positive or negative symbiosis when coscheduled without requiring

Eeckhout, Lieven

217

Probabilistic Job Symbiosis Modeling for SMT Processor Scheduling  

E-print Network

Probabilistic Job Symbiosis Modeling for SMT Processor Scheduling Stijn Eyerman Lieven Eeckhout a sampling phase, evaluate a limited number of possible co-schedules, use heuristics to gauge symbiosis proposes probabilistic job symbiosis modeling, which predicts whether jobs will create positive or negative

Eeckhout, Lieven

218

REGULAR ARTICLE Testing the ecological stability of ectomycorrhizal symbiosis  

E-print Network

REGULAR ARTICLE Testing the ecological stability of ectomycorrhizal symbiosis: effects of heat, ash symbiosis, elevated nutrient levels may make the carbon cost to plants of supporting mycorrhizal fungi-fire nutrient enrichment on the ectomy- corrhizal symbiosis between Rhizopogon occidentalis and Pinus muricata

Silver, Whendee

219

Biology of Symbiosis (BIOL 256), Fall 2005 Instructor: David Hibbett  

E-print Network

Biology of Symbiosis (BIOL 256), Fall 2005 SYLLABUS Instructor: David Hibbett Contact: e: Surindar Paracer and Vernon Ahmadjian. 2000. Symbiosis, An Introduction to Biological Associations. Second the land and establish terrestrial ecosystems. Symbiosis is a major source of evolutionary and ecological

Hibbett, David S.

220

Robotic room: Symbiosis with human through behavior media  

Microsoft Academic Search

This paper discusses difference between conventional industrial robotics and human symbiosis robotics considering human characteristics. It clarifies necessary robotic functions in the human symbiosis robots. The functions are: (1) sharing mental activities, (2) sharing behavior, and (3) sharing physiological activities between the human and the robot. As a typical example of a human robot symbiosis system, the authors propose a

Tomomasa Sato; Yoshifumi Nishida; Hiroshi Mizoguchi

1996-01-01

221

Elevated Temperature and Drought Interact to Reduce Parasitoid Effectiveness in Suppressing Hosts  

PubMed Central

Climate change affects the abundance, distribution and activity of natural enemies that are important for suppressing herbivore crop pests. Moreover, higher mean temperatures and increased frequency of climatic extremes are expected to induce different responses across trophic levels, potentially disrupting predator-prey interactions. Using field observations, we examined the response of an aphid host-parasitoid system to variation in temperature. Temperature was positively associated with attack rates by parasitoids, but also with a non-significant trend towards increased attack rates by higher-level hyperparasitoids. Elevated hyperparasitism could partly offset any benefit of climate warming to parasitoids, and would suggest that higher trophic levels may hamper predictions of predator-prey interactions. Additionally, the mechanisms affecting host-parasitoid dynamics were examined using controlled laboratory experiments that simulated both temperature increase and drought. Parasitoid fitness and longevity responded differently when exposed to each climatic variable in isolation, compared to the interaction of both variables at once. Although temperature increase or drought tended to positively affect the ability of parasitoids to control aphid populations, these effects were significantly reversed when the drivers were expressed in concert. Additionally, separate warming and drought treatments reduced parasitoid longevity, and although temperature increased parasitoid emergence success and drought increased offspring production, combined temperature and drought produced the lowest parasitoid emergence. The non-additive effects of different climate drivers, combined with differing responses across trophic levels, suggest that predicting future pest outbreaks will be more challenging than previously imagined. PMID:23472147

Romo, Cecilia M.; Tylianakis, Jason M.

2013-01-01

222

Microbial Symbiosis: In Sickness and in Health In this special issue, we explore the theme of symbiosis  

E-print Network

EDITORIAL Microbial Symbiosis: In Sickness and in Health In this special issue, we explore the theme of symbiosis between eukaryotic hosts and their microbial associates. These invited contributions to keep populations of cheaters in check. In another binary symbiosis, Blochmannia and insects

Ruby, Edward G.

223

Bacterial Leaf Symbiosis in Angiosperms: Host Specificity without Co-Speciation  

PubMed Central

Bacterial leaf symbiosis is a unique and intimate interaction between bacteria and flowering plants, in which endosymbionts are organized in specialized leaf structures. Previously, bacterial leaf symbiosis has been described as a cyclic and obligate interaction in which the endosymbionts are vertically transmitted between plant generations and lack autonomous growth. Theoretically this allows for co-speciation between leaf nodulated plants and their endosymbionts. We sequenced the nodulated Burkholderia endosymbionts of 54 plant species from known leaf nodulated angiosperm genera, i.e. Ardisia, Pavetta, Psychotria and Sericanthe. Phylogenetic reconstruction of bacterial leaf symbionts and closely related free-living bacteria indicates the occurrence of multiple horizontal transfers of bacteria from the environment to leaf nodulated plant species. This rejects the hypothesis of a long co-speciation process between the bacterial endosymbionts and their host plants. Our results indicate a recent evolutionary process towards a stable and host specific interaction confirming the proposed maternal transmission mode of the endosymbionts through the seeds. Divergence estimates provide evidence for a relatively recent origin of bacterial leaf symbiosis, dating back to the Miocene (5–23 Mya). This geological epoch was characterized by cool and arid conditions, which may have triggered the origin of bacterial leaf symbiosis. PMID:21915326

Lemaire, Benny; Vandamme, Peter; Merckx, Vincent; Smets, Erik; Dessein, Steven

2011-01-01

224

The symbiont side of symbiosis: do microbes really benefit?  

PubMed Central

Microbial associations are integral to all eukaryotes. Mutualism, the interaction of two species for the benefit of both, is an important aspect of microbial associations, with evidence that multicellular organisms in particular benefit from microbes. However, the microbe’s perspective has largely been ignored, and it is unknown whether most microbial symbionts benefit from their associations with hosts. It has been presumed that microbial symbionts receive host-derived nutrients or a competition-free environment with reduced predation, but there have been few empirical tests, or even critical assessments, of these assumptions. We evaluate these hypotheses based on available evidence, which indicate reduced competition and predation are not universal benefits for symbionts. Some symbionts do receive nutrients from their host, but this has not always been linked to a corresponding increase in symbiont fitness. We recommend experiments to test symbiont fitness using current experimental systems of symbiosis and detail considerations for other systems. Incorporating symbiont fitness into symbiosis research will provide insight into the evolution of mutualistic interactions and cooperation in general. PMID:25309530

Garcia, Justine R.; Gerardo, Nicole M.

2014-01-01

225

Explorations in Symbiosis on two Multithreaded Architectures  

E-print Network

Explorations in Symbiosis on two Multithreaded Architectures Allan Snavely \\Lambday , Nick Mitchell are executed concurrently on a multithreaded computer. In this paper, we give a formal definition of symbio­ sis, make observations about its nature, and present experimental results on two multithreaded

Wang, Deli

226

Predator-prey relationships among larval dragonflies, salamanders, and frogs  

Microsoft Academic Search

Tadpoles of the barking tree frog, Hyla gratiosa, are abundant in spring and summer in some ponds and Carolina bays on the Savannah River Plant near Aiken, South Carolina. To determine how these tadpoles survive in the presence of predaceous salamander larvae, Ambystoma talpoideum, and larvae of an aeshnid dragonfly, Anax junius, we determined fields densities and sizes of the

J. P. Caldwell; J. H. Thorp; T. O. Jervey

1980-01-01

227

SCIENCE IN ACTION! Nature's Partners: predators, prey & you  

E-print Network

and the Technology Assisted Learning Lab at T A&M U i it F t h i l i t t t th T h l A i t d L i L b t (979) 862 3449 iTexas A&M University. For technical assistance contact theTechnology Assisted Learning Lab at (979

Packard, Jane M.

228

Trait-mediated diversification in nematode predator-prey systems.  

PubMed

Nematodes are presumably the most numerous Metazoans in terrestrial habitats. They are represented at all trophic levels and are known to respond to nutrient limitation, prey availability, and microbial resources. Predatory nematodes reside at the highest trophic level, and as such their feeding habits could have a major impact on soil food web functioning. Here, we investigate the effects of gender and developmental stage on the nematode body sizes in coarse and loamy soils. Besides Neodiplogasteridae, our predators are much larger than other soil-dwelling nematodes from their early developmental stage onwards. From juvenile to adult, the predatory Aporcelaimellus (Kruskal-Wallis P < 0.001), Dorylaimoides, and Tripyla (both P < 0.01) show great length increases during their developmental growth, in contrast to their possible prey (almost all P < 0.001). Less than 4% of the prey exceeds the length of the predatory adults, but more than 30% of the prey exceeds the length of the predatory juveniles. Potential body size ratios and some physical problems experienced by small fluid feeders attacking large prey are discussed in an attempt to summarize different prey-searching mechanisms and aggregative predatory responses in the soil system. PMID:22393508

Mulder, Christian; Helder, Johannes; Vervoort, Mariëtte T W; Arie Vonk, J

2011-11-01

229

Cyclic Genetic Algorithm with Conditional Branching PredatorPrey Scenario  

E-print Network

generation, genetic algorithm, hexapod Introduction Evolving controllers autonomous legged robots reduce levels. CGAs were successfully past evolve single­loop robot cycles cycles hexapod robots area coverage

Parker, Gary B.

230

Bifurcations and dynamics of a discrete predator-prey system  

PubMed Central

In this paper, we study the dynamics behaviour of a stratum of plant–herbivore which is modelled through the following F(x, y)=(f(x, y), g(x, y)) two-dimensional map with four parameters defined by where x?0, y?0, and the real parameters a, b, r, k are all positive. We will focus on the case a?b. We study the stability of fixed points and do the analysis of the period-doubling and the Neimark–Sacker bifurcations in a standard way. PMID:24963984

Asheghi, Rasoul

2014-01-01

231

A Predator-Prey Model with Disease Dynamics Chris Flake  

E-print Network

high temperature, massive algae growth, high salinity, pollution, and low dissolved oxygen levels that the bacterial infection contributes to low oxygen levels in the tissues of the infected fish. The shortage of oxygen causes the fish to seek oxygen from the sea's surface and leads to a favorable environment

Logan, David

232

Spatial Geographic Mosaic in an Aquatic Predator-Prey Network  

PubMed Central

The geographic mosaic theory of coevolution predicts 1) spatial variation in predatory structures as well as prey defensive traits, and 2) trait matching in some areas and trait mismatching in others mediated by gene flow. We examined gene flow and documented spatial variation in crushing resistance in the freshwater snails Mexipyrgus churinceanus, Mexithauma quadripaludium, Nymphophilus minckleyi, and its relationship to the relative frequency of the crushing morphotype in the trophically polymorphic fish Herichthys minckleyi. Crushing resistance and the frequency of the crushing morphotype did show spatial variation among 11 naturally replicated communities in the Cuatro Ciénegas valley in Mexico where these species are all endemic. The variation in crushing resistance among populations was not explained by geographic proximity or by genetic similarity in any species. We detected clear phylogeographic patterns and limited gene flow for the snails but not for the fish. Gene flow among snail populations in Cuatro Ciénegas could explain the mosaic of local divergence in shell strength and be preventing the fixation of the crushing morphotype in Herichthys minckleyi. Finally, consistent with trait matching across the mosaic, the frequency of the fish morphotype was negatively correlated with shell crushing resistance likely reflecting the relative disadvantage of the crushing morphotype in communities where the snails exhibit relatively high crushing resistance. PMID:21799865

Chaves-Campos, Johel; Johnson, Steven G.; Hulsey, C. Darrin

2011-01-01

233

Nature's Partners: predators, prey & you SCIENCE IN ACTION!  

E-print Network

thinking analytically like a scientist, by separating objective observations from subjective inference. UseMEASURE DATA GENERAL LEARNING GOAL: Experience the nature of scientific inquiry (observation, measurements

Packard, Jane M.

234

Diminished exoproteome of Frankia spp. in culture and symbiosis.  

PubMed

Frankia species are the most geographically widespread gram-positive plant symbionts, carrying out N(2) fixation in root nodules of trees and woody shrubs called actinorhizal plants. Taking advantage of the sequencing of three Frankia genomes, proteomics techniques were used to investigate the population of extracellular proteins (the exoproteome) from Frankia, some of which potentially mediate host-microbe interactions. Initial two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of culture supernatants indicated that cytoplasmic proteins appeared in supernatants as cells aged, likely because older hyphae lyse in this slow-growing filamentous actinomycete. Using liquid chromatography coupled to tandem mass spectrometry to identify peptides, 38 proteins were identified in the culture supernatant of Frankia sp. strain CcI3, but only three had predicted export signal peptides. In symbiotic cells, 42 signal peptide-containing proteins were detected from strain CcI3 in Casuarina cunninghamiana and Casuarina glauca root nodules, while 73 and 53 putative secreted proteins containing signal peptides were identified from Frankia strains in field-collected root nodules of Alnus incana and Elaeagnus angustifolia, respectively. Solute-binding proteins were the most commonly identified secreted proteins in symbiosis, particularly those predicted to bind branched-chain amino acids and peptides. These direct proteomics results complement a previous bioinformatics study that predicted few secreted hydrolytic enzymes in the Frankia proteome and provide direct evidence that the symbiosis succeeds partly, if not largely, because of a benign relationship. PMID:19749056

Mastronunzio, J E; Huang, Y; Benson, D R

2009-11-01

235

Diminished Exoproteome of Frankia spp. in Culture and Symbiosis ? †  

PubMed Central

Frankia species are the most geographically widespread gram-positive plant symbionts, carrying out N2 fixation in root nodules of trees and woody shrubs called actinorhizal plants. Taking advantage of the sequencing of three Frankia genomes, proteomics techniques were used to investigate the population of extracellular proteins (the exoproteome) from Frankia, some of which potentially mediate host-microbe interactions. Initial two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of culture supernatants indicated that cytoplasmic proteins appeared in supernatants as cells aged, likely because older hyphae lyse in this slow-growing filamentous actinomycete. Using liquid chromatography coupled to tandem mass spectrometry to identify peptides, 38 proteins were identified in the culture supernatant of Frankia sp. strain CcI3, but only three had predicted export signal peptides. In symbiotic cells, 42 signal peptide-containing proteins were detected from strain CcI3 in Casuarina cunninghamiana and Casuarina glauca root nodules, while 73 and 53 putative secreted proteins containing signal peptides were identified from Frankia strains in field-collected root nodules of Alnus incana and Elaeagnus angustifolia, respectively. Solute-binding proteins were the most commonly identified secreted proteins in symbiosis, particularly those predicted to bind branched-chain amino acids and peptides. These direct proteomics results complement a previous bioinformatics study that predicted few secreted hydrolytic enzymes in the Frankia proteome and provide direct evidence that the symbiosis succeeds partly, if not largely, because of a benign relationship. PMID:19749056

Mastronunzio, J. E.; Huang, Y.; Benson, D. R.

2009-01-01

236

Getting What Is Served? Feeding Ecology Influencing Parasite-Host Interactions in Invasive Round Goby Neogobius melanostomus  

PubMed Central

Freshwater ecosystems are increasingly impacted by alien invasive species which have the potential to alter various ecological interactions like predator-prey and host-parasite relationships. Here, we simultaneously examined predator-prey interactions and parasitization patterns of the highly invasive round goby (Neogobius melanostomus) in the rivers Rhine and Main in Germany. A total of 350 N. melanostomus were sampled between June and October 2011. Gut content analysis revealed a broad prey spectrum, partly reflecting temporal and local differences in prey availability. For the major food type (amphipods), species compositions were determined. Amphipod fauna consisted entirely of non-native species and was dominated by Dikerogammarus villosus in the Main and Echinogammarus trichiatus in the Rhine. However, the availability of amphipod species in the field did not reflect their relative abundance in gut contents of N. melanostomus. Only two metazoan parasites, the nematode Raphidascaris acus and the acanthocephalan Pomphorhynchus sp., were isolated from N. melanostomus in all months, whereas unionid glochidia were only detected in June and October in fish from the Main. To analyse infection pathways, we examined 17,356 amphipods and found Pomphorhynchus sp. larvae only in D. villosus in the river Rhine at a prevalence of 0.15%. Dikerogammarus villosus represented the most important amphipod prey for N. melanostomus in both rivers but parasite intensities differed between rivers, suggesting that final hosts (large predatory fishes) may influence host-parasite dynamics of N. melanostomus in its introduced range. PMID:25338158

Emde, Sebastian; Kochmann, Judith; Kuhn, Thomas; Plath, Martin; Klimpel, Sven

2014-01-01

237

Symbiosis, competition, and physical disturbance in the growth histories of Pliocene cheilostomebryoliths  

E-print Network

Symbiosis, competition, and physical disturbance in the growth histories of Pliocene cheilostomebryoliths SUSANM. KIDWELL AND ERIC D. GYLLENHAAL LETHAIA Kidwell, S.M. & Gyllenhaal,E.D. 199809 15:Symbiosis. OBryozoa, symbiosis, competition, paleoecology, taphonomy. Susan M. Kidwell [skidwell

Boyce, C. Kevin

238

Phylogenyofarbuscular mycorrhizal fungi predicts community composition of symbiosis-associated bacteria  

E-print Network

Phylogenyofarbuscular mycorrhizal fungi predicts community composition of symbiosis by the symbiosis-accompanying bacterial communities, a possibility that should be explicitly considered in studies fungi can also differentially influence soil bacterial communities associated with the symbiosis (e

Rilli, Matthias C.

239

The determinants of the actinorhizal symbiosis.  

PubMed

The actinorhizal symbiosis is a major contributor to the global nitrogen budget, playing a dominant role in ecological successions following disturbances. The mechanisms involved are still poorly known but there emerges the vision that on the plant side, the kinases that transmit the symbiotic signal are conserved with those involved in the transmission of the Rhizobium Nod signal in legumes. However, on the microbial side, complementation with Frankia DNA of Rhizobium nod mutants failed to permit identification of symbiotic genes. Furthermore, analysis of three Frankia genomes failed to permit identification of canonical nod genes and revealed symbiosis-associated genes such as nif, hup, suf and shc to be spread around the genomes. The present review explores some recently published approaches aimed at identifying bacterial symbiotic determinants. PMID:21576879

Kucho, Ken-Ichi; Hay, Anne-Emmanuelle; Normand, Philippe

2010-01-01

240

Long-distance transport of signals during symbiosis  

PubMed Central

Legumes enter nodule symbioses with nitrogen-fixing bacteria (rhizobia), whereas most flowering plants establish symbiotic associations with arbuscular mycorrhizal (AM) fungi. Once first steps of symbiosis are initiated, nodule formation and mycorrhization in legumes is negatively controlled by a shoot-derived inhibitor (SDI), a phenomenon termed autoregulation. According to current views, autoregulation of nodulation and mycorrhization in legumes is regulated in a similar way. CLE peptides induced in response to rhizobial nodulation signals (Nod factors) have been proposed to represent the ascending long-distance signals to the shoot. Although not proven yet, these CLE peptides are likely perceived by leucine-rich repeat (LRR) autoregulation receptor kinases in the shoot. Autoregulation of mycorrhization in non-legumes is reminiscent to the phenomenon of “systemic acquired resistance” in plant-pathogen interactions. PMID:21455020

Xie, Zhi-Ping; Illana, Antonio

2011-01-01

241

Structural basis for regulation of rhizobial nodulation and symbiosis gene expression by the regulatory protein NolR  

PubMed Central

The symbiosis between rhizobial microbes and host plants involves the coordinated expression of multiple genes, which leads to nodule formation and nitrogen fixation. As part of the transcriptional machinery for nodulation and symbiosis across a range of Rhizobium, NolR serves as a global regulatory protein. Here, we present the X-ray crystal structures of NolR in the unliganded form and complexed with two different 22-base pair (bp) double-stranded operator sequences (oligos AT and AA). Structural and biochemical analysis of NolR reveals protein–DNA interactions with an asymmetric operator site and defines a mechanism for conformational switching of a key residue (Gln56) to accommodate variation in target DNA sequences from diverse rhizobial genes for nodulation and symbiosis. This conformational switching alters the energetic contributions to DNA binding without changes in affinity for the target sequence. Two possible models for the role of NolR in the regulation of different nodulation and symbiosis genes are proposed. To our knowledge, these studies provide the first structural insight on the regulation of genes involved in the agriculturally and ecologically important symbiosis of microbes and plants that leads to nodule formation and nitrogen fixation. PMID:24733893

Lee, Soon Goo; Krishnan, Hari B.; Jez, Joseph M.

2014-01-01

242

Defoliation effects on Plantago lanceolata resource allocation and soil decomposers in relation to AM symbiosis and fertilization  

Microsoft Academic Search

Plants can mediate interactions between aboveground herbivores and belowground decomposers as both groups depend on plant-provided organic carbon. Most vascular plants also form symbiosis with arbuscular mycorrhizal fungi (AMF), which compete for plant carbon too. Our aim was to reveal how defoliation (trimming of plant leaves twice to 6 cm above the soil surface) and mycorrhizal infection (inoculation of the fungus

Anne Pietikäinen; Juha Mikola; Mauritz Vestberg; Heikki Setälä

2009-01-01

243

Sugar for my honey: Carbohydrate partitioning in ectomycorrhizal symbiosis  

E-print Network

Review Sugar for my honey: Carbohydrate partitioning in ectomycorrhizal symbiosis Uwe Nehls a, readily utilizable carbohydrates, necessary for growth and maintenance of large numbers of microbes, a symbiosis between tree roots and certain soil fungi, is a way to overcome nutrient and carbohydrate

Bruns, Tom

244

DNA amplification fingerprinting of the Azolla-Anabaena symbiosis  

Microsoft Academic Search

The Azolla-Anabaena symbiosis has been used for centuries as a nitrogen biofertilizer in rice paddies. Genetic improvement of the symbiosis has been limited by the difficulty in identifying Azolla-Anabaena accessions and Anabaena azollae strains. The recently developed technique of DNA amplification fingerprinting (DAF) was applied to this problem. DAF uses single, short, oligonucleotide primers of arbitrary sequence to direct amplification

D. L. Eskew; G. Caetano-Anollés; B. J. Bassam; P. M. Gresshoff

1993-01-01

245

The anemonefish symbiosis: what is known and what is not  

E-print Network

by fish for hosts, and chance. One benefit of the symbiosis to the fish is obvious:its major source of protection is its anemone, which forms the core of its territory. The symbiosis has commonly been regarded as facultative for actinians. However...

Fautin, Daphne G.

1991-01-01

246

Shifting species interactions in terrestrial dryland ecosystems under altered water availability and climate change  

USGS Publications Warehouse

Species interactions play key roles in linking the responses of populations, communities, and ecosystems to environmental change. For instance, species interactions are an important determinant of the complexity of changes in trophic biomass with variation in resources. Water resources are a major driver of terrestrial ecology and climate change is expected to greatly alter the distribution of this critical resource. While previous studies have documented strong effects of global environmental change on species interactions in general, responses can vary from region to region. Dryland ecosystems occupy more than one-third of the Earth's land mass, are greatly affected by changes in water availability, and are predicted to be hotspots of climate change. Thus, it is imperative to understand the effects of environmental change on these globally significant ecosystems. Here, we review studies of the responses of population-level plant-plant, plant-herbivore, and predator-prey interactions to changes in water availability in dryland environments in order to develop new hypotheses and predictions to guide future research. To help explain patterns of interaction outcomes, we developed a conceptual model that views interaction outcomes as shifting between (1) competition and facilitation (plant-plant), (2) herbivory, neutralism, or mutualism (plant-herbivore), or (3) neutralism and predation (predator-prey), as water availability crosses physiological, behavioural, or population-density thresholds. We link our conceptual model to hypothetical scenarios of current and future water availability to make testable predictions about the influence of changes in water availability on species interactions. We also examine potential implications of our conceptual model for the relative importance of top-down effects and the linearity of patterns of change in trophic biomass with changes in water availability. Finally, we highlight key research needs and some possible broader impacts of our findings. Overall, we hope to stimulate and guide future research that links changes in water availability to patterns of species interactions and the dynamics of populations and communities in dryland ecosystems.

McCluney, Kevin E.; Belnap, Jayne; Collins, Scott L.; González, Angélica L.; Hagen, Elizabeth M.; Holland, J. Nathaniel; Kotler, Burt P.; Maestre, Fernando T.; Smith, Stanley D.; Wolf, Blair O.

2012-01-01

247

Interaction strengths in balanced carbon cycles and the absence of a relation between ecosystem complexity and stability.  

PubMed

The strength of interactions is crucial to the stability of ecological networks. However, the patterns of interaction strengths in mathematical models of ecosystems have not yet been based upon independent observations of balanced material fluxes. Here we analyse two Antarctic ecosystems for which the interaction strengths are obtained: (1) directly, from independently measured material fluxes, (2) for the complete ecosystem and (3) with a close match between species and 'trophic groups'. We analyse the role of recycling, predation and competition and find that ecosystem stability can be estimated by the strengths of the shortest positive and negative predator-prey feedbacks in the network. We show the generality of our explanation with another 21 observed food webs, comparing random-type parameterisations of interaction strengths with empirical ones. Our results show how functional relationships dominate over average-network topology. They make clear that the classic complexity-instability paradox is essentially an artificial interaction-strength result. PMID:24636521

Neutel, Anje-Margriet; Thorne, Michael A S

2014-06-01

248

Host-microbial symbiosis in the vertebrate gastrointestinal tract and the Lactobacillus reuteri paradigm  

PubMed Central

Vertebrates engage in symbiotic associations with vast and complex microbial communities that colonize their gastrointestinal tracts. Recent advances have provided mechanistic insight into the important contributions of the gut microbiome to vertebrate biology, but questions remain about the evolutionary processes that have shaped symbiotic interactions in the gut and the consequences that arise for both the microbes and the host. Here we discuss the biological principles that underlie microbial symbiosis in the vertebrate gut and the potential of the development of mutualism. We then review phylogenetic and experimental studies on the vertebrate symbiont Lactobacillus reuteri that have provided novel insight into the ecological and evolutionary strategy of a gut microbe and its relationship with the host. We argue that a mechanistic understanding of the microbial symbiosis in the vertebrate gut and its evolution will be important to determine how this relationship can go awry, and it may reveal possibilities by which the gut microbiome can be manipulated to support health. PMID:20615995

Walter, Jens; Britton, Robert A.; Roos, Stefan

2011-01-01

249

Self-Stabilizable Symbiosis for Cloud Data Center Applications: A Game Theoretic Perspective  

E-print Network

Self-Stabilizable Symbiosis for Cloud Data Center Applications: A Game Theoretic Perspective selection, emergence and symbiosis. In SymbioticSphere, each data center application consists of application (or symbiosis) between them. A symbiosis between a service and a platform is sought as a Nash

Suzuki, Jun

250

Nuclear calcium changes at the core of symbiosis signalling Giles ED Oldroyd and J Allan Downie  

E-print Network

Nuclear calcium changes at the core of symbiosis signalling Giles ED Oldroyd and J Allan Downie for the mycorrhizal symbiosis. This suggests that different symbiosis-specific signalling pathways are activated of the plant responses associated with nodulation [5]. In the mycorrhizal symbiosis, there is evidence of two

Downie, J. Allan

251

Spatio-temporal dynamics of a three interacting species mathematical model inspired in physics  

NASA Astrophysics Data System (ADS)

In this paper we study both, analytically and numerically, the spatio-temporal dynamics of a three interacting species mathematical model. The populations take the form of pollinators, a plant and herbivores; the model consists of three nonlinear reaction-diffusion-advection equations. In view of considering the full model, as a previous step we firstly analyze a mutualistic interaction (pollinator-plant), later on a predator-prey (plant-herbivore) interaction model is studied and finally, we consider the full model. In all cases, the purely temporal dynamics is given; meanwhile for the spatio-temporal dynamics, we use numerical simulations, corresponding to those parameter values for which we obtain interesting temporal dynamics.

Sánchez-Garduño, Faustino; Breña-Medina, Víctor F.

2008-02-01

252

Oak root response to ectomycorrhizal symbiosis establishment: RNA-Seq derived transcript identification and expression profiling.  

PubMed

Ectomycorrhizal symbiosis is essential for the life and health of trees in temperate and boreal forests where it plays a major role in nutrient cycling and in functioning of the forest ecosystem. Trees with ectomycorrhizal root tips are more tolerant to environmental stresses, such as drought, and biotic stresses such as root pathogens. Detailed information on these molecular processes is essential for the understanding of symbiotic tissue development in order to optimize the benefits of this natural phenomenon. Next generation sequencing tools allow the analysis of non model ectomycorrhizal plant-fungal interactions that can contribute to find the "symbiosis toolkits" and better define the role of each partner in the mutualistic interaction. By using 454 pyrosequencing we compared ectomycorrhizal cork oak roots with non-symbiotic roots. From the two cDNA libraries sequenced, over 2 million reads were obtained that generated 19,552 cork oak root unique transcripts. A total of 2238 transcripts were found to be differentially expressed when ECM roots were compared with non-symbiotic roots. Identification of up- and down-regulated gens in ectomycorrhizal roots lead to a number of insights into the molecular mechanisms governing this important symbiosis. In cork oak roots, ectomycorrhizal colonization resulted in extensive cell wall remodelling, activation of the secretory pathway, alterations in flavonoid biosynthesis, and expression of genes involved in the recognition of fungal effectors. In addition, we identified genes with putative roles in symbiotic processes such as nutrient exchange with the fungal partner, lateral root formation or root hair decay. These findings provide a global overview of the transcriptome of an ectomycorrhizal host root, and constitute a foundation for future studies on the molecular events controlling this important symbiosis. PMID:24859293

Sebastiana, Mónica; Vieira, Bruno; Lino-Neto, Teresa; Monteiro, Filipa; Figueiredo, Andreia; Sousa, Lisete; Pais, Maria Salomé; Tavares, Rui; Paulo, Octávio S

2014-01-01

253

Oak Root Response to Ectomycorrhizal Symbiosis Establishment: RNA-Seq Derived Transcript Identification and Expression Profiling  

PubMed Central

Ectomycorrhizal symbiosis is essential for the life and health of trees in temperate and boreal forests where it plays a major role in nutrient cycling and in functioning of the forest ecosystem. Trees with ectomycorrhizal root tips are more tolerant to environmental stresses, such as drought, and biotic stresses such as root pathogens. Detailed information on these molecular processes is essential for the understanding of symbiotic tissue development in order to optimize the benefits of this natural phenomenon. Next generation sequencing tools allow the analysis of non model ectomycorrhizal plant-fungal interactions that can contribute to find the “symbiosis toolkits” and better define the role of each partner in the mutualistic interaction. By using 454 pyrosequencing we compared ectomycorrhizal cork oak roots with non-symbiotic roots. From the two cDNA libraries sequenced, over 2 million reads were obtained that generated 19552 cork oak root unique transcripts. A total of 2238 transcripts were found to be differentially expressed when ECM roots were compared with non-symbiotic roots. Identification of up- and down-regulated gens in ectomycorrhizal roots lead to a number of insights into the molecular mechanisms governing this important symbiosis. In cork oak roots, ectomycorrhizal colonization resulted in extensive cell wall remodelling, activation of the secretory pathway, alterations in flavonoid biosynthesis, and expression of genes involved in the recognition of fungal effectors. In addition, we identified genes with putative roles in symbiotic processes such as nutrient exchange with the fungal partner, lateral root formation or root hair decay. These findings provide a global overview of the transcriptome of an ectomycorrhizal host root, and constitute a foundation for future studies on the molecular events controlling this important symbiosis. PMID:24859293

Lino-Neto, Teresa; Monteiro, Filipa; Figueiredo, Andreia; Sousa, Lisete; Pais, Maria Salome; Tavares, Rui; Paulo, Octavio S.

2014-01-01

254

Microfungal "weeds" in the leafcutter ant symbiosis.  

PubMed

Leafcutter ants (Formicidae: tribe Attini) are well-known insects that cultivate basidiomycete fungi (Agaricales: Lepiotaceae) as their principal food. Fungus gardens are monocultures of a single cultivar strain, but they also harbor a diverse assemblage of additional microbes with largely unknown roles in the symbiosis. Cultivar-attacking microfungi in the genus Escovopsis are specialized parasites found only in association with attine gardens. Evolutionary theory predicts that the low genetic diversity in monocultures should render ant gardens susceptible to a wide range of diseases, and additional parasites with roles similar to that of Escovopsis are expected to exist. We profiled the diversity of cultivable microfungi found in 37 nests from ten Acromyrmex species from Southern Brazil and compared this diversity to published surveys. Our study revealed a total of 85 microfungal strains. Fusarium oxysporum and Escovopsis were the predominant species in the surveyed gardens, infecting 40.5% and 27% of the nests, respectively. No specific relationship existed regarding microfungal species and ant-host species, ant substrate preference (dicot versus grass) or nesting habit. Molecular data indicated high genetic diversity among Escovopsis isolates. In contrast to the garden parasite, F. oxysporum strains are not specific parasites of the cultivated fungus because strains isolated from attine gardens have similar counterparts found in the environment. Overall, the survey indicates that saprophytic microfungi are prevalent in South American leafcutter ants. We discuss the antagonistic potential of these microorganisms as "weeds" in the ant-fungus symbiosis. PMID:18369523

Rodrigues, A; Bacci, M; Mueller, U G; Ortiz, A; Pagnocca, F C

2008-11-01

255

Cell wall remodeling in mycorrhizal symbiosis: a way towards biotrophism  

PubMed Central

Cell walls are deeply involved in the molecular talk between partners during plant and microbe interactions, and their role in mycorrhizae, i.e., the widespread symbiotic associations established between plant roots and soil fungi, has been investigated extensively. All mycorrhizal interactions achieve full symbiotic functionality through the development of an extensive contact surface between the plant and fungal cells, where signals and nutrients are exchanged. The exchange of molecules between the fungal and the plant cytoplasm takes place both through their plasma membranes and their cell walls; a functional compartment, known as the symbiotic interface, is thus defined. Among all the symbiotic interfaces, the complex intracellular interface of arbuscular mycorrhizal (AM) symbiosis has received a great deal of attention since its first description. Here, in fact, the host plasma membrane invaginates and proliferates around all the developing intracellular fungal structures, and cell wall material is laid down between this membrane and the fungal cell surface. By contrast, in ectomycorrhizae (ECM), where the fungus grows outside and between the root cells, plant and fungal cell walls are always in direct contact and form the interface between the two partners. The organization and composition of cell walls within the interface compartment is a topic that has attracted widespread attention, both in ecto- and endomycorrhizae. The aim of this review is to provide a general overview of the current knowledge on this topic by integrating morphological observations, which have illustrated cell wall features during mycorrhizal interactions, with the current data produced by genomic and transcriptomic approaches. PMID:24926297

Balestrini, Raffaella; Bonfante, Paola

2014-01-01

256

Assess suitability of hydroaeroponic culture to establish tripartite symbiosis between different AMF species, beans, and rhizobia  

PubMed Central

Background Like other species of the Phaseoleae tribe, common bean (Phaseolus vulgaris L.) has the potential to establish symbiosis with rhizobia and to fix the atmospheric dinitrogen (N2) for its N nutrition. Common bean has also the potential to establish symbiosis with arbuscular mycorrhizal fungi (AMF) that improves the uptake of low mobile nutrients such as phosphorus, from the soil. Both rhizobial and mycorrhizal symbioses can act synergistically in benefits on plant. Results The tripartite symbiosis of common bean with rhizobia and arbuscular mycorrhizal fungi (AMF) was assessed in hydroaeroponic culture with common bean (Phaseolus vulgaris L.), by comparing the effects of three fungi spp. on growth, nodulation and mycorrhization of the roots under sufficient versus deficient P supplies, after transfer from initial sand culture. Although Glomus intraradices Schenck & Smith colonized intensely the roots of common bean in both sand and hydroaeroponic cultures, Gigaspora rosea Nicolson & Schenck only established well under sand culture conditions, and no root-colonization was found with Acaulospora mellea Spain & Schenck under either culture conditions. Interestingly, mycorrhization by Glomus was also obtained by contact with mycorrhized Stylosanthes guianensis (Aubl.) sw in sand culture under deficient P before transfer into hydroaeroponic culture. The effect of bean genotype on both rhizobial and mycorrhizal symbioses with Glomus was subsequently assessed with the common bean recombinant inbreed line 7, 28, 83, 115 and 147, and the cultivar Flamingo. Significant differences among colonization and nodulation of the roots and growth among genotypes were found. Conclusion The hydroaeroponic culture is a valuable tool for further scrutinizing the physiological interactions and nutrient partitioning within the tripartite symbiosis. PMID:19534785

Tajini, Fatma; Suriyakup, Porntip; Vailhe, Helene; Jansa, Jan; Drevon, Jean-Jacques

2009-01-01

257

The Genome of Laccaria Bi color Provides Insights into Mycorrhizal Symbiosis  

SciTech Connect

Mycorrhizal symbioses the union of roots and soil fungi are universal in terrestrial ecosystems and may have been fundamental to land colonization by plants1,2. Boreal, temperate and montane forests all depend on ectomycorrhizae1. Identification of the primary factors that regulate symbiotic development and metabolic activity will therefore open the door to understanding the role of ectomycorrhizae in plant development and physiology, allowing the full ecological significance of this symbiosis to be explored. Here we report the genome sequence of the ectomycorrhizal basidiomycete Laccaria bicolor (Fig. 1) and highlight gene sets involved in rhizosphere colonization and symbiosis. This 65-megabase genome assembly contains 20,000 predicted protein-encoding genes and a very large number of transposons and repeated sequences. We detected unexpected genomic features, most notably a battery of effector-type small secreted proteins (SSPs) with unknown function, several of which are only expressed in symbiotic tissues. The most highly expressed SSP accumulates in the proliferating hyphae colonizing the host root. The ectomycorrhizae-specific SSPs probably have a decisive role in the establishment of the symbiosis. The unexpected observation that the genome of L. bicolor lacks carbohydrate-active enzymes involved in degradation of plant cell walls, but maintains the ability to degrade non-plant cell wall polysaccharides, reveals the dual saprotrophic and biotrophic lifestyle of the mycorrhizal fungus that enables it to grow within both soil and living plant roots. The predicted gene inventory of the L. bicolor genome, therefore, points to previously unknown mechanisms of symbiosis operating in biotrophic mycorrhizal fungi. The availability of this genome provides an unparalleled opportunity to develop a deeper understanding of the processes by which symbionts interact with plants within their ecosystem to perform vital functions in the carbon and nitrogen cycles that are fundamental to sustainable plant productivity.

Martin, F [UMR, France; Aerts, A. [U.S. Department of Energy, Joint Genome Institute; Ahren, D [Lund University, Sweden; Brun, A [UMR, France; Duchaussoy, F [UMR, France; Gibon, J [UMR, France; Kohler, A [UMR, France; Lindquist, E [U.S. Department of Energy, Joint Genome Institute; Pereda, V [UMR, France; Salamov, A. [U.S. Department of Energy, Joint Genome Institute; Shapiro, HJ [U.S. Department of Energy, Joint Genome Institute; Wuyts, J [UMR, France; Blaudez, D [UMR, France; Buee, M [UMR, France; Brokstein, P [U.S. Department of Energy, Joint Genome Institute; Canbeck, B [Lund University, Sweden; Cohen, D [UMR, France; Courty, PE [UMR, France; Coutinho, PM [Architecture et Fonction des Macromolecules Biologiques, UMR 6098 CNRS and Unive; Danchin, E [Architecture et Fonction des Macromolecules Biologiques, UMR 6098 CNRS and Unive; Delaruelle, C [UMR, France; Detter, J C [U.S. Department of Energy, Joint Genome Institute; Deveau, A [UMR, France; DiFazio, Stephen P [West Virginia University; Duplessis, S [UMR, France; Fraissinet-Tachet, L [Universite de Lyon, France; Lucic, E [UMR, France; Frey-Klett, P [UMR, France; Fourrey, C [UMR, France; Feussner, I [Georg-August Universitat Gottingen Germany; Gay, G [Universite de Lyon, France; Grimwood, Jane [Stanford University; Hoegger, P J [Georg-August Universitat Gottingen Germany; Jain, P [University of Alabama, Huntsville; Kilaru, S [Georg-August Universitat Gottingen Germany; Labbe, J [UMR, France; Lin, Y C [Ghent University, Belgium; Legue, V [UMR, France; Le Tacon, F [UMR, France; Marmeisse, R [Universite de Lyon, France; Melayah, D [Universite de Lyon, France; Montanini, B [UMR, France; Muratet, M [University of Alabama, Huntsville; Nehls, U [Eberhard-Karls-Universitat, Tubingen, Germany; Niculita-Hirzel, H [University of Lausanne, Switzerland; Oudot-Le Secq, M P [UMR, France; Peter, M [UMR, France; Quesneville, H [Unite de Recherches en Genomique-Info,Evry Cedex; Rajashekar, B [Lund University, Sweden; Reich, M [UMR, France; Rouhler, N [UMR, France; Schmutz, Jeremy [Stanford University; Yin, Tongming [ORNL; Chalot, M [UMR, France; Henrissat, B [Architecture et Fonction des Macromolecules Biologiques, UMR 6098 CNRS and Unive; Kues, U [Georg-August Universitat Gottingen Germany; Lucas, S [U.S. Department of Energy, Joint Genome Institute; Van de Peer, Y [Ghent University, Belgium; Podila, G [University of Alabama, Huntsville; Polle, A [Georg-August Universitat Gottingen Germany; Pukkila, P J [University of North Carolina, Chapel Hill; Richardson, P M [U.S. Department of Energy, Joint Genome Institute; Rouze, P [Ghent University, Belgium; Sanders, I R [University of Lausanne, Switzerland; Stajich, J E [University of California, Berkeley; Tunlid, A [Lund University, Sweden; Tuskan, Gerald A [ORNL; Grigoriev, I. [U.S. Department of Energy, Joint Genome Institute

2008-01-01

258

Naïveté in novel ecological interactions: lessons from theory and experimental evidence.  

PubMed

The invasion of alien species into areas beyond their native ranges is having profound effects on ecosystems around the world. In particular, novel alien predators are causing rapid extinctions or declines in many native prey species, and these impacts are generally attributed to ecological naïveté or the failure to recognise a novel enemy and respond appropriately due to a lack of experience. Despite a large body of research concerning the recognition of alien predation risk by native prey, the literature lacks an extensive review of naïveté theory that specifically asks how naïveté between novel pairings of alien predators and native prey disrupts our classical understanding of predator-prey ecological theory. Here we critically review both classic and current theory relating to predator-prey interactions between both predators and prey with shared evolutionary histories, and those that are ecologically 'mismatched' through the outcomes of biological invasions. The review is structured around the multiple levels of naïveté framework of Banks & Dickman (2007), and concepts and examples are discussed as they relate to each stage in the process from failure to recognise a novel predator (Level 1 naïveté), through to appropriate (Level 2) and effective (Level 3) antipredator responses. We discuss the relative contributions of recognition, cue types and the implied risk of cues used by novel alien and familiar native predators, to the probability that prey will recognise a novel predator. We then cover the antipredator response types available to prey and the factors that predict whether these responses will be appropriate or effective against novel alien and familiar native predators. In general, the level of naïveté of native prey can be predicted by the degree of novelty (in terms of appearance, behaviour or habitat use) of the alien predator compared to native predators with which prey are experienced. Appearance in this sense includes cue types, spatial distribution and implied risk of cues, whilst behaviour and habitat use include hunting modes and the habitat domain of the predator. Finally, we discuss whether the antipredator response can occur without recognition per se, for example in the case of morphological defences, and then consider a potential extension of the multiple levels of naïveté framework. The review concludes with recommendations for the design and execution of naïveté experiments incorporating the key concepts and issues covered here. This review aims to critique and combine classic ideas about predator-prey interactions with current naïveté theory, to further develop the multiple levels of naïveté framework, and to suggest the most fruitful avenues for future research. PMID:25319946

Carthey, Alexandra J R; Banks, Peter B

2014-11-01

259

Quantifying potential industrial symbiosis : a case study of brick manufacturing  

E-print Network

Humanity is currently on an unsustainable path of growth and development. One tool to address sustainability in industrial activities is Industrial Symbiosis, which is the study of cooperation across industry boundaries ...

Hodge, Matthew M

2007-01-01

260

Experimental Study on Interaction between a Rat and a Rat-robot based on Animal Psychology - Analysis of Basic Factors Necessary for a Symbiosis between the Rat and the Robot  

Microsoft Academic Search

We clarify the basic factors necessary for a symbiotic relationship between humans and robots. However, evaluating interaction between humans and robots is difficult due to a number of uncertain factors in human communication. Therefore, less sophisticated creatures, rats, were first selected, and we conducted interaction experiments between rats and robots. In our previous studies, we could not conduct these experiments

Hiroyuki Ishii; Tomohide Aoki; Masaki Nakasuji; Hiroyasu Miwa; Atsuo Takanishi

2004-01-01

261

Determinant factors of industrial symbiosis: greening Pasir Gudang industrial park  

NASA Astrophysics Data System (ADS)

Green industry has been identified as an important element in attaining greater sustainability. It calls for harmonizing robust economic growth with environment protection. Industries, particularly in developing and transitional nations such as Malaysia, are in need of a reform. Many experts and international organizations suggest the concept of industrial symbiosis. Mainly, there are successful cases of industrial symbiosis practices around the world. However, there are numerous cases of failure too. As industrial symbiosis is an emerging new approach, with a short history of two decades, a lot of researches are generally focused on narrow context and technical details. There is a lack of concerted efforts to look into the drivers and barriers of industrial symbiosis across different cases. This paper aims to examine the factors influencing the development of industrial symbiosis from various countries to supports such networks to evolve in Pasir Gudang. The findings show institution, law and regulation, finance, awareness and capacity building, technology, research and development, information, collaboration, market, geography proximity, environmental issues and industry structure affect the formation of industrial symbiosis.

Teh, B. T.; Ho, C. S.; Matsuoka, Y.; Chau, L. W.; Gomi, K.

2014-02-01

262

The University of Chicago The Direct and Ecological Costs of an Ant-Plant Symbiosis.  

E-print Network

The University of Chicago The Direct and Ecological Costs of an Ant-Plant Symbiosis. Author and Ecological Costs of an Ant-Plant Symbiosis Megan E. Frederickson,1, * Alison Ravenscraft,2 Gabriel A. Miller

Pierce, Naomi E.

263

A Genomic Reappraisal of Symbiotic Function in the Aphid/Buchnera Symbiosis: Reduced Transporter Sets  

E-print Network

A Genomic Reappraisal of Symbiotic Function in the Aphid/Buchnera Symbiosis: Reduced Transporter Function in the Aphid/Buchnera Symbiosis: Reduced Transporter Sets and Variable Membrane Organisations. PLo

Paris-Sud XI, Université de

264

Tree-mycorrhiza symbiosis accelerate mineral weathering: Evidences from nanometer-scale elemental fluxes  

E-print Network

Tree-mycorrhiza symbiosis accelerate mineral weathering: Evidences from nanometer-scale elemental in revised form 29 August 2011 Abstract In soils, mycorrhiza (microscopic fungal hypha) living in symbiosis

Benning, Liane G.

265

Different soil moisture conditions change the outcome of the ectomycorrhizal symbiosis between Rhizopogon species and Pinus muricata  

Microsoft Academic Search

The outcome of species interactions often depends on the environmental conditions under which they occur. In this study, we\\u000a tested how different soil moisture conditions affected the outcome of the ectomycorrhizal symbiosis between three Rhizopogon species and Pinus muricata in a factorial growth chamber experiment. We found that when grown in 7% soil moisture conditions, ectomycorrhizal plants\\u000a had similar biomass,

Peter G. Kennedy; Kabir G. Peay

2007-01-01

266

Testing the ecological stability of ectomycorrhizal symbiosis: effects of heat, ash and mycorrhizal colonization on Pinus muricata seedling performance  

Microsoft Academic Search

Understanding how abiotic conditions mediate the outcome of biotic interactions is a key question in community ecology. This\\u000a is particularly interesting in the case of mutualisms because changing environmental conditions may be a source of evolutionary\\u000a or ecological instability in the relationship between symbiotic partners. For the mycorrhizal symbiosis, elevated nutrient\\u000a levels may make the carbon cost to plants of

Kabir G. Peay; Thomas D. Bruns; Matteo Garbelotto

2010-01-01

267

Bacterial communities associated with the lichen symbiosis.  

PubMed

Lichens are commonly described as a mutualistic symbiosis between fungi and "algae" (Chlorophyta or Cyanobacteria); however, they also have internal bacterial communities. Recent research suggests that lichen-associated microbes are an integral component of lichen thalli and that the classical view of this symbiotic relationship should be expanded to include bacteria. However, we still have a limited understanding of the phylogenetic structure of these communities and their variability across lichen species. To address these knowledge gaps, we used bar-coded pyrosequencing to survey the bacterial communities associated with lichens. Bacterial sequences obtained from four lichen species at multiple locations on rock outcrops suggested that each lichen species harbored a distinct community and that all communities were dominated by Alphaproteobacteria. Across all samples, we recovered numerous bacterial phylotypes that were closely related to sequences isolated from lichens in prior investigations, including those from a lichen-associated Rhizobiales lineage (LAR1; putative N(2) fixers). LAR1-related phylotypes were relatively abundant and were found in all four lichen species, and many sequences closely related to other known N(2) fixers (e.g., Azospirillum, Bradyrhizobium, and Frankia) were recovered. Our findings confirm the presence of highly structured bacterial communities within lichens and provide additional evidence that these bacteria may serve distinct functional roles within lichen symbioses. PMID:21169444

Bates, Scott T; Cropsey, Garrett W G; Caporaso, J Gregory; Knight, Rob; Fierer, Noah

2011-02-01

268

Cannibalism in larvae of the long-toed salamander, Ambystoma macrodactylum.  

E-print Network

??Predator-prey interactions have historically been studied to explain patterns of organization observed in populations and communities. They have also been important in understanding the evolution… (more)

Wildy, Erica Lynn

2000-01-01

269

DELLA proteins regulate arbuscule formation in arbuscular mycorrhizal symbiosis.  

PubMed

Most flowering plants are able to form endosymbioses with arbuscular mycorrhizal fungi. In this mutualistic association, the fungus colonizes the root cortex and establishes elaborately branched hyphae, called arbuscules, within the cortical cells. Arbuscule development requires the cellular reorganization of both symbionts, and the resulting symbiotic interface functions in nutrient exchange. A plant symbiosis signaling pathway controls the development of the symbiosis. Several components of the pathway have been identified, but transcriptional regulators that control downstream pathways for arbuscule formation are still unknown. Here we show that DELLA proteins, which are repressors of gibberellic acid (GA) signaling and function at the nexus of several signaling pathways, are required for arbuscule formation. Arbuscule formation is severely impaired in a Medicago truncatula Mtdella1/Mtdella2 double mutant; GA treatment of wild-type roots phenocopies the della double mutant, and a dominant DELLA protein (della1-?18) enables arbuscule formation in the presence of GA. Ectopic expression of della1-?18 suggests that DELLA activity in the vascular tissue and endodermis is sufficient to enable arbuscule formation in the inner cortical cells. In addition, expression of della1-?18 restores arbuscule formation in the symbiosis signaling pathway mutant cyclops/ipd3, indicating an intersection between DELLA and symbiosis signaling for arbuscule formation. GA signaling also influences arbuscule formation in monocots, and a Green Revolution wheat variety carrying dominant DELLA alleles shows enhanced colonization but a limited growth response to arbuscular mycorrhizal symbiosis. PMID:24297892

Floss, Daniela S; Levy, Julien G; Lévesque-Tremblay, Véronique; Pumplin, Nathan; Harrison, Maria J

2013-12-17

270

A review of industrial symbiosis research: theory and methodology  

NASA Astrophysics Data System (ADS)

The theory, methodologies, and case studies in the field of industrial symbiosis have been developing for nearly 30 years. In this paper, we trace the development history of industrial symbiosis, and review its current theoretical and methodological bases, as well as trends in current research. Based on the research gaps that we identify, we provide suggestions to guide the future development of this approach to permit more comprehensive analyses. Our theoretical review includes key definitions, a classification system, and a description of the formation and development mechanisms. We discuss methodological studies from the perspective of individual industrial metabolic processes and network analysis. Analyzing specific metabolic processes can help to characterize the exchanges of materials and energy, and to reveal the ecological performance and economic benefits of the symbiosis. Network analysis methods are increasingly being used to analyze both the structural and functional characteristics of a system. Our suggestions for future research focus on three aspects: how to quantitatively classify industrial symbiosis systems, monitor the dynamics of a developing industrial symbiosis system, and analyze its internal attributes more deeply.

Zhang, Yan; Zheng, Hongmei; Chen, Bin; Su, Meirong; Liu, Gengyuan

2014-06-01

271

Symbionticism and Complex Adaptive Systems I: Implications of Having Symbiosis Occur in Nature  

Microsoft Academic Search

Over the past several years, there has been an increasing interest in the biological phenomena of symbiosis by those in complex adaptive systems and evolutionary computation. We describe in this paper some of the caveats involved in modeling or using biological symbiosis as a computational metaphor. We specifically consider some of the common philosophical viewpoints on symbiosis and comment on

Jason M. Daida; Catherine S. Grasso; Stephen A. Stanhope; Steven J. Ross

1996-01-01

272

Roles of Bacterial Regulators in the Symbiosis between Vibrio fischeri and Euprymna scolopes  

E-print Network

Roles of Bacterial Regulators in the Symbiosis between Vibrio fischeri and Euprymna scolopes 1 Introduction In a symbiosis, two or more evolutionarily distinct organisms communicate with one another in order to co-exist and co-adapt in their shared environment. The mutualistic symbiosis between

McFall-Ngai, Margaret

273

Fungal and algal gene expression in early developmental stages of lichen-symbiosis  

E-print Network

Fungal and algal gene expression in early developmental stages of lichen-symbiosis Suzanne Joneson1 of the central questions in cellular communication. The symbiosis between the filamen- tous fungus Cladonia grayi the development of the lichen symbiosis. The results of this study highlight future avenues of investigation

Lutzoni, François M.

274

A jetdisk symbiosis model for Gamma Ray Bursts: fluence distribution, CRs  

E-print Network

A jet­disk symbiosis model for Gamma Ray Bursts: fluence distribution, CRs and š's G. Pugliese 1­disk symbiosis model to explain Gamma Ray Bursts and their afterglows. It is proposed that GRBs are created ideas of the jet­disk symbiosis model by Falcke & Biermann [6]. In this model, accretion disk, jet

Falcke, Heino

275

Reference: Bid. Bull. 189: 347-355. (December, 1995) A Transient Exposure to Symbiosis-Competent  

E-print Network

Reference: Bid. Bull. 189: 347-355. (December, 1995) A Transient Exposure to Symbiosis and the luminous bacterium Vibrio Jischeri have shown that colonization of juvenile squid with symbiosis that a transient, 12-hour exposure to symbiosis-competent bacteria is necessary and sufficient to induce tissue

McFall-Ngai, Margaret

276

Study of Cnidarian-Algal Symbiosis in the "Omics" Age , AND VIRGINIA M. WEIS*  

E-print Network

Study of Cnidarian-Algal Symbiosis in the "Omics" Age ELI MEYER* , AND VIRGINIA M. WEIS* Department with the symbiotic state. Here we review the history of "omics" studies of cnidarian-algal symbiosis and the current- osis across 10 anthozoan species. The public availability of candidate symbiosis-associated genes

277

Musica ex Machina: Composing 16th-Century Counter-point with Genetic Programming and Symbiosis  

E-print Network

1 Musica ex Machina: Composing 16th-Century Counter- point with Genetic Programming and Symbiosis a symbiosis-inspired genetic programming paradigm in which distinct agents collaborate to produce 16th introduces our current software program, GPmuse, and focuses on both the implementation of a symbiosis

Fernandez, Thomas

278

Range Expansion Drives Dispersal Evolution In An Equatorial Three-Species Symbiosis  

E-print Network

Range Expansion Drives Dispersal Evolution In An Equatorial Three-Species Symbiosis Guillaume Le-species symbiosis endemic to coastal equatorial rainforests in Cameroon, where the impact of range dynamics species, there was no evidence of destabilization of the symbiosis at the colonization front. To our

Paris-Sud XI, Université de

279

SYMBIOSIS: Development, Implementation, and Assessment of a Model Curriculum across Biology  

E-print Network

Article SYMBIOSIS: Development, Implementation, and Assessment of a Model Curriculum across Biology this three-semester curriculum, known as SYMBIOSIS. This curriculum was piloted to two student cohorts during to implement the SYMBIOSIS curriculum as a replacement for the standard biology majors curriculum

Karsai, Istvan

280

Proteomic and transcriptional analyses of coral larvae newly engaged in symbiosis with dinoflagellates  

E-print Network

Proteomic and transcriptional analyses of coral larvae newly engaged in symbiosis, such as stony corals, engage in intracellular symbiosis with dinoflagellates, forming the trophic and structural and the transcriptome of larvae of the Hawaiian solitary coral Fungia scutaria during the onset of symbiosis

281

Symbiosis Winter 2004 Sponsor: Erik V. Thuesen, x6584, Lab I 3065, thuesene@evergreen.edu  

E-print Network

1 Symbiosis Winter 2004 Sponsor: Erik V. Thuesen, x6584, Lab I 3065, thuesene@evergreen.edu Lab books Symbiosis: an introduction to biological associations by Surindar Paracer and Vernon Ahmadjian of the bioluminescent symbiosis between Photobacterium leiognathi and leiognathid fish. Annals of the N.Y. Acad

Thuesen, Erik V.

282

Multiple factors contribute to keeping levels of the symbiosis regulator RscS low  

E-print Network

Multiple factors contribute to keeping levels of the symbiosis regulator RscS low Kati Geszvain Abstract Increased activity alleles (rscS1 and rscS2) of the symbiosis regulator RscS induced both syp host. Keywords Sensor kinase; histidine kinase; RscS; polysaccharide; symbiosis Introduction Two

McFall-Ngai, Margaret

283

FeatureC++: On the Symbiosis of Feature-Oriented and Aspect-Oriented  

E-print Network

FeatureC++: On the Symbiosis of Feature-Oriented and Aspect-Oriented Programming Sven Apel, Thomas of this article are our investigations in the symbiosis of FOP and AOP. Our aim is to combine the strengths #12;to do this symbiosis (as we will explain): Multi Mixins, Aspectual Mixin Layers, and Aspectual

Apel, Sven

284

AM symbiosis alters phenolic acid content in tomato roots  

PubMed Central

Arbuscular mycorrhizal (AM) fungi colonize the roots of most plants to establish a mutualistic symbiosis leading to important benefits for plant health. We have recently shown that AM symbiosis alters both transcriptional and hormonal profiles in tomato roots, many of these changes related to plant defense. Here, we analytically demonstrate that the levels of other important defense-related compounds as phenolic acids are also altered in the symbiosis. Both caffeic and chlorogenic acid levels significantly decreased in tomato roots upon mycorrhization, while ferulic acid increased. Moreover, in the case of caffeic acid a differential reduction was observed depending on the colonizing AM fungus. The results confirm that AM associations imply the regulation of plant defense responses, and that the host changes may vary depending on the AM fungus involved. The potential implications of altered phenolic acid levels on plant control over mycorrhizal colonization and in the plant resistance to pathogens is discussed. PMID:21490421

Flors, Victor; Garcia, Juan M; Pozo, Maria J

2010-01-01

285

Symbiosis Teaching Workshop -5th International Symbiosis Society Congress, Vienna, August 4-10, 2006 LL A BA B AA C T I V I T YC T I V I T Y  

E-print Network

Symbiosis Teaching Workshop - 5th International Symbiosis Society Congress, Vienna, August 4 Genus: Azolla Subgenus: Azolla Section: Azolla Species: Azolla filiculoides #12;Symbiosis Teaching Workshop - 5th International Symbiosis Society Congress, Vienna, August 4-10, 2006 2 Azolla is a small

Carrapiço, Francisco

286

Preventing overexploitation in a mutualism: partner regulation in the crayfish-branchiobdellid symbiosis.  

PubMed

For a symbiosis to be a mutualism, benefits received must exceed costs incurred for both partners. Partners can prevent costly overexploitation through behaviors that moderate interactions with the other symbiont. In a symbiosis between crayfish and branchiobdellidan annelids, the worms can increase crayfish survival and growth by removing fouling material from the gills. However, overexploitation by the worms is possible and results in damage to host gills. We used behavioral observations to assess the degree to which two species of crayfish (Cambarus chasmodactylus and Orconectes cristavarius) use grooming to moderate their interaction with branchiobdellids. We found that grooming could effectively reduce worm numbers, and the proportion of total grooming directed at worms differed between crayfish species and as a function of worm number. O. cristavarius increased grooming in response to the addition of a single worm, while C. chasmodactylus only increased grooming in response to ten worms. These differences in the number of worms that trigger grooming behavior reflect differences between crayfish species in field settings. We also assessed whether antibacterial compounds in circulating crayfish hemolymph could limit bacterial gill fouling. O. cristavarius hemolymph inhibited some test bacteria more effectively than C. chasmodactylus did. Differences in the antibacterial properties of crayfish hemolymph may therefore help explain differences in both worm-directed grooming and worm loads in the field. We conclude that crayfish can use grooming to reduce worm numbers, which could lower the potential for gill damage, and that the level of grooming varies between crayfish species. PMID:24072440

Farrell, Kaitlin J; Creed, Robert P; Brown, Bryan L

2014-02-01

287

Phytoremediation of heavy and transition metals aided by legume-rhizobia symbiosis.  

PubMed

Legumes are important for nitrogen cycling in the environment and agriculture due to the ability of nitrogen fixation by rhizobia. In this review, we introduce an important and potential role of legume-rhizobia symbiosis in aiding phytoremediation of some metal contaminated soils as various legumes have been found to be the dominant plant species in metal contaminated areas. Resistant rhizobia used for phytoremediation could act on metals directly by chelation, precipitation, transformation, biosorption and accumulation. Moreover, the plant growth promoting (PGP) traits of rhizobia including nitrogen fixation, phosphorus solubilization, phytohormone synthesis, siderophore release, and production of ACC deaminase and the volatile compounds of acetoin and 2, 3-butanediol may facilitate legume growth while lessening metal toxicity. The benefits of using legumes inoculated with naturally resistant rhizobia or recombinant rhizobia with enhanced resistance, as well as co-inoculation with other plant growth promoting bacteria (PGPB) are discussed. However, the legume-rhizobia symbiosis appears to be sensitive to metals, and the effect of metal toxicity on the interaction between legumes and rhizobia is not clear. Therefore, to obtain the maximum benefits from legumes assisted by rhizobia for phytoremediation of metals, it is critical to have a good understanding of interactions between PGP traits, the symbiotic plant-rhizobia relationship and metals. PMID:24912209

Hao, X; Taghavi, S; Xie, P; Orbach, M J; Alwathnani, H A; Rensing, C; Wei, G

2014-01-01

288

Genomic analysis reveals key aspects of prokaryotic symbiosis in the phototrophic consortium "Chlorochromatium aggregatum"  

PubMed Central

Background ‘Chlorochromatium aggregatum’ is a phototrophic consortium, a symbiosis that may represent the highest degree of mutual interdependence between two unrelated bacteria not associated with a eukaryotic host. ‘Chlorochromatium aggregatum’ is a motile, barrel-shaped aggregate formed from a single cell of ‘Candidatus Symbiobacter mobilis”, a polarly flagellated, non-pigmented, heterotrophic bacterium, which is surrounded by approximately 15 epibiont cells of Chlorobium chlorochromatii, a non-motile photolithoautotrophic green sulfur bacterium. Results We analyzed the complete genome sequences of both organisms to understand the basis for this symbiosis. Chl. chlorochromatii has acquired relatively few symbiosis-specific genes; most acquired genes are predicted to modify the cell wall or function in cell-cell adhesion. In striking contrast, ‘Ca. S. mobilis’ appears to have undergone massive gene loss, is probably no longer capable of independent growth, and thus may only reproduce when consortia divide. A detailed model for the energetic and metabolic bases of the dependency of ‘Ca. S. mobilis’ on Chl. chlorochromatii is described. Conclusions Genomic analyses suggest that three types of interactions lead to a highly sophisticated relationship between these two organisms. Firstly, extensive metabolic exchange, involving carbon, nitrogen, and sulfur sources as well as vitamins, occurs from the epibiont to the central bacterium. Secondly, ‘Ca. S. mobilis’ can sense and move towards light and sulfide, resources that only directly benefit the epibiont. Thirdly, electron cycling mechanisms, particularly those mediated by quinones and potentially involving shared protonmotive force, could provide an important basis for energy exchange in this and other symbiotic relationships. PMID:24267588

2013-01-01

289

Singular Features of the Bradyrhizobium-Lupinus Symbiosis  

Microsoft Academic Search

Lupinus is a legume with great agronomic potential due to the high protein content of its seeds and its positive effect on soil fertility. It is able to fix atmospheric nitrogen through the establishment of a symbiosis with soil bacteria of the genus Bradyrhizobium. The process is carried out in a special subclass of indeterminate nodules known as lupinoid nodules.

Mercedes Fernández-Pascual; José J. PueyoMaría; M. Mercedes Lucas

290

Host–Bacterial Symbiosis in Health and Disease  

Microsoft Academic Search

All animals live in symbiosis. Shaped by eons of co-evolution, host-bacterial associations have developed into prosperous relationships creating mechanisms for mutual benefits to both microbe and host. No better example exists in biology than the astounding numbers of bacteria harbored by the lower gastrointestinal tract of mammals. The mammalian gut represents a complex ecosystem consisting of an extraordinary number of

Janet Chow; S. Melanie Lee; Yue Shen; Arya Khosravi; Sarkis K. Mazmanian

2010-01-01

291

Ectomycorrhizal symbiosis affects functional diversity of rhizosphere fluorescent pseudomonads  

Microsoft Academic Search

Summary • Here we characterized the effect of the ectomycorrhizal symbiosis on the genotypic and functional diversity of soil Pseudomonas fluorescens populations and analysed its possible consequences in terms of plant nutrition, development and health. • Sixty strains of P. fluorescens were isolated from the bulk soil of a forest nursery, the ectomycorrhizosphere and the ectomycorrhizas of the Douglas fir

Pascale Frey-Klett; Michaël Chavatte; Marie-Lise Clausse; Sébastien Courrier; Christine Le Roux; Jos Raaijmakers; Maria Giovanna Martinotti; Jean-Claude Pierrat; Jean Garbaye

2004-01-01

292

Ectomycorrhizal symbiosis affects functional diversity of rhizosphere fluorescent pseudomonads  

Microsoft Academic Search

Here we characterized the effect of the ectomycorrhizal symbiosis on the genotypic and functional diversity of soil Pseudomonas fluorescens populations and analysed its possible consequences in terms of plant nutrition, development and health. ¿ Sixty strains of P. fluorescens were isolated from the bulk soil of a forest nursery, the ectomycorrhizosphere and the ectomycorrhizas of the Douglas fir (Pseudostuga menziesii)

P. Frey-Klett; M. Chavatte; M. L. Clausse; S. Courrier; Roux Le C; J. M. Raaijmakers; M. Giovanna Martinotti; J. C. Pierrat; J. Garbaye

2005-01-01

293

Quorum Sensing in the Squid-Vibrio Symbiosis  

PubMed Central

Quorum sensing is an intercellular form of communication that bacteria use to coordinate group behaviors such as biofilm formation and the production of antibiotics and virulence factors. The term quorum sensing was originally coined to describe the mechanism underlying the onset of luminescence production in cultures of the marine bacterium Vibrio fischeri. Luminescence and, more generally, quorum sensing are important for V. fischeri to form a mutualistic symbiosis with the Hawaiian bobtail squid, Euprymna scolopes. The symbiosis is established when V. fischeri cells migrate via flagella-based motility from the surrounding seawater into a specialized structure injuvenile squid called the light organ. The cells grow to high cell densities within the light organ where the infection persists over the lifetime of the animal. A hallmark of a successful symbiosis is the luminescence produced by V. fischeri that camouflages the squid at night by eliminating its shadow within the water column. While the regulatory networks governing quorum sensing are critical for properly regulating V. fischeri luminescence within the squid light organ, they also regulate luminescence-independent processes during symbiosis. In this review, we discuss the quorum-sensing network of V. fischeri and highlight its impact at various stages during host colonization. PMID:23965960

Verma, Subhash C.; Miyashiro, Tim

2013-01-01

294

The Rhizobium-pea symbiosis as affected by high temperatures  

Microsoft Academic Search

A study has been made concerning the effect of high temperatures on the symbiosis of Rhizobium leguminosarum and pea plants (Pisum sativum). At 30°C, no nodules were found on the roots of plants growing in nutrient solution after inoculation with the appropriate bacteria. This is in contrast to the ready nodulation at lower temperatures, and to the observation that at

J. F. J. Frings

1976-01-01

295

Plant demographic responses to mycorrhizal symbiosis in tallgrass prairie  

Microsoft Academic Search

The effects of mycorrhizal symbiosis on seedling emergence, flowering and densities of several grasses and forbs were assessed in native tallgrass prairie and in sown garden populations at the Konza Prairie in northeastern Kansas. Mycorrhizal activity was experimentally suppressed with the fungicide benomyl. Flowering and stem densities of the cool-season grass, Dichanthelium oligosanthes, sedges (Carex spp.), and the forb Aster

D. C. Hartnett; R. J. Samenus; L. E. Fischer; B. A. D. Hetrick

1994-01-01

296

Bacterial symbiosis in Loripes lucinalis (Mollusca: Bivalvia)with comments  

E-print Network

Symbiotic chemoautotrophic bacteria occur in the tissues of a number of invertebrates where sulphide relationships, there are still many unanswered questions. Does the host bene¢t from the symbiosis via direct or not the host can vary its nutritional dependence on the symbiotic bacteria. Obtaining clear answers

Boyer, Edmond

297

Evaluation of Project Symbiosis: An Interdisciplinary Science Education Project.  

ERIC Educational Resources Information Center

The goal of this report is to provide a summary of the evaluation of Project Symbiosis which focused on enhancing the teaching of science principles in high school agriculture courses. The project initially involved 15 teams of science and agriculture teachers and was characterized by an extensive evaluation component consisting of six formal…

Altschuld, James W.

1993-01-01

298

Reporters and Congressmen: Living in Symbiosis. Journalism Monographs No. 53.  

ERIC Educational Resources Information Center

Although philosophers in the United States have advocated the concept of adversarity for the relationship between reporters and people in Congress, in actuality these two groups work together in symbiosis. This document reports on a study in which 190 reporters, members of Congress, and Congressional aides were interviewed regarding particular…

Miller, Susan Heilmann

299

Methanotrophic marine molluscan (Bivalvia, Mytilidae) symbiosis: mussels fueled by gas  

Microsoft Academic Search

An undescribed mussel (family Mytilidae), which lives in the vicinity of hydrocarbon seeps in the Gulf of Mexico, consumes methane (the principal component of natural gas) at a high rate. The methane consumption is limited to the gills of these animals and is apparently due to the abundant intracellular bacteria found there. This demonstrates a methane-based symbiosis between an animal

J. J. Childress; C. R. Fisher; J. M. Brooks; M. C. II Kennicutt; R. Bidigare; A. E. Anderson

1986-01-01

300

A study of evolutionary multiagent models based on symbiosis  

Microsoft Academic Search

Multiagent Systems with Symbiotic Learning and Evolution (Masbiole) has been proposed and studied, which is a new methodology of Multiagent Systems (MAS) based on symbiosis in the ecosystem. Masbiole employs a method of symbiotic learning and evolution where agents can learn or evolve according to their symbiotic relations toward others, i.e., considering the benefits\\/losses of both itself and an opponent.

Toru Eguchi; Kotaro Hirasawa; Jinglu Hu; Nathan Ota

2006-01-01

301

Vision based gesture recognition for human-robot symbiosis  

Microsoft Academic Search

This paper presents a vision based gesture recognition system for human-robot symbiosis. The system is based on the visual information of the face and is commenced with the recognition of face gesture by connected component analysis of the skin color segmentation of images in HSV color model and neural network based pattern-matching strategies. On gesture recognition, robot is being instructed

M. A.-A. Bhuiyan; M. E. Islam; Nasima Begum; M. Hasanuzzaman; Chang Hong Liu; H. Ueno

2007-01-01

302

On Gesture Recognition for Human-Robot Symbiosis  

Microsoft Academic Search

This paper presents a vision based gesture recognition system for human-robot symbiosis. The system is based on visual information of the face gestures recognition by connected component analysis of the skin color segmentation of images in HSV color model and PCA based pattern-matching strategies. On gesture recognition, the robot is being instructed to perform certain tasks by issuing commands. The

M. Al-Amin Bhuiyan

2006-01-01

303

Quorum sensing in the squid-Vibrio symbiosis.  

PubMed

Quorum sensing is an intercellular form of communication that bacteria use to coordinate group behaviors such as biofilm formation and the production of antibiotics and virulence factors. The term quorum sensing was originally coined to describe the mechanism underlying the onset of luminescence production in cultures of the marine bacterium Vibrio fischeri. Luminescence and, more generally, quorum sensing are important for V. fischeri to form a mutualistic symbiosis with the Hawaiian bobtail squid, Euprymna scolopes. The symbiosis is established when V. fischeri cells migrate via flagella-based motility from the surrounding seawater into a specialized structure injuvenile squid called the light organ. The cells grow to high cell densities within the light organ where the infection persists over the lifetime of the animal. A hallmark of a successful symbiosis is the luminescence produced by V. fischeri that camouflages the squid at night by eliminating its shadow within the water column. While the regulatory networks governing quorum sensing are critical for properly regulating V. fischeri luminescence within the squid light organ, they also regulate luminescence-independent processes during symbiosis. In this review, we discuss the quorum-sensing network of V. fischeri and highlight its impact at various stages during host colonization. PMID:23965960

Verma, Subhash C; Miyashiro, Tim

2013-01-01

304

Leeches and their microbiota: naturally simple symbiosis models  

Microsoft Academic Search

Strictly blood-feeding leeches and their limited microbiota provide natural and powerful model systems to examine symbiosis. Blood is devoid of essential nutri- ents and it is thought that symbiotic bacteria synthesize these for the host. In this review, three distinct leech- microbe associations are described: (i) the mycetome, which is the large symbiont-containing organ associated with the esophagus; (ii) the

Joerg Graf; Yoshitomo Kikuchi; Rita V. M. Rio

2006-01-01

305

Social interactions, predation behaviour and fast start performance are affected by ammonia exposure in brown trout (Salmo trutta L.).  

PubMed

In fish, fast starts are brief, sudden accelerations during predator-prey encounters. They serve for escape and predation and are therefore ecologically important movements. Fast starts are generated by glycolytic muscle performance and are influenced by many internal and external factors. It is known that ammonia pollution has a major effect on the glycolytic muscle action, thus creating conditions in which fast start performance might be reduced and predation rates altered. Therefore, escape response and predation strikes were investigated in brown trout (Salmo trutta) of 10 and 20 cm body length exposed to an elevated (1 mg l(-1)) ammonia concentration for 24 and 96 h. Various locomotor and behavioural variables were measured. In C-starts, i.e. an escape start where the fish bends into a C-shaped position, ammonia exposure had no effect on response latency. After 96 h of exposure, cumulative distance, maximum swimming speed and turning radius of the prey were all significantly reduced and the escape went in no definite direction. The effect of ammonia exposure was more pronounced in large fish than in small fish. Predation strikes were also affected. Distance, speed and turning radius were significantly lower in exposed fish. Agonistic behaviour of dominant fish was significantly reduced and fish spent more time resting. Predator behaviour was also altered and the number of prey captured was reduced. This study shows that ammonia exposure affects brown trout escape response mainly through a reduction in fast start velocity and through an impairment of directionality. Thus, in addition to a reduced strength of the response, ammonia exposure could also reduce the fish's elusiveness facing a predator. Predation rate and social interactions are disrupted and predator-prey relationships could be altered. PMID:18829121

Tudorache, Christian; Blust, R; De Boeck, G

2008-11-11

306

Aeschynomene evenia, a model plant for studying the molecular genetics of the nod-independent rhizobium-legume symbiosis.  

PubMed

Research on the nitrogen-fixing symbiosis has been focused, thus far, on two model legumes, Medicago truncatula and Lotus japonicus, which use a sophisticated infection process involving infection thread formation. However, in 25% of the legumes, the bacterial entry occurs more simply in an intercellular fashion. Among them, some Aeschynomene spp. are nodulated by photosynthetic Bradyrhizobium spp. that do not produce Nod factors. This interaction is believed to represent a living testimony of the ancestral state of the rhizobium-legume symbiosis. To decipher the mechanisms of this Nod-independent process, we propose Aeschynomene evenia as a model legume because it presents all the characteristics required for genetic and molecular analysis. It is a short-perennial and autogamous species, with a diploid and relatively small genome (2n=20; 460 Mb/1C). A. evenia 'IRFL6945' is nodulated by the well-characterized photosynthetic Bradyrhizobium sp. strain ORS278 and is efficiently transformed by Agrobacterium rhizogenes. Aeschynomene evenia is genetically homozygous but polymorphic accessions were found. A manual hybridization procedure has been set up, allowing directed crosses. Therefore, it should be relatively straightforward to unravel the molecular determinants of the Nod-independent process in A. evenia. This should shed new light on the evolution of rhizobium-legume symbiosis and could have important agronomic implications. PMID:22475377

Arrighi, Jean-François; Cartieaux, Fabienne; Brown, Spencer C; Rodier-Goud, Marguerite; Boursot, Marc; Fardoux, Joel; Patrel, Delphine; Gully, Djamel; Fabre, Sandrine; Chaintreuil, Clémence; Giraud, Eric

2012-07-01

307

Bacterial symbiosis maintenance in the asexually reproducing and regenerating flatworm Paracatenula galateia.  

PubMed

Bacteriocytes set the stage for some of the most intimate interactions between animal and bacterial cells. In all bacteriocyte possessing systems studied so far, de novo formation of bacteriocytes occurs only once in the host development, at the time of symbiosis establishment. Here, we present the free-living symbiotic flatworm Paracatenula galateia and its intracellular, sulfur-oxidizing bacteria as a system with previously undescribed strategies of bacteriocyte formation and bacterial symbiont transmission. Using thymidine analogue S-phase labeling and immunohistochemistry, we show that all somatic cells in adult worms - including bacteriocytes - originate exclusively from aposymbiotic stem cells (neoblasts). The continued bacteriocyte formation from aposymbiotic stem cells in adult animals represents a previously undescribed strategy of symbiosis maintenance and makes P. galateia a unique system to study bacteriocyte differentiation and development. We also provide morphological and immunohistochemical evidence that P. galateia reproduces by asexual fragmentation and regeneration (paratomy) and, thereby, vertically transmits numerous symbiont-containing bacteriocytes to its asexual progeny. Our data support the earlier reported hypothesis that the symbiont population is subjected to reduced bottleneck effects. This would justify both the codiversification between Paracatenula hosts and their Candidatus Riegeria symbionts, and the slow evolutionary rates observed for several symbiont genes. PMID:22509347

Dirks, Ulrich; Gruber-Vodicka, Harald R; Leisch, Nikolaus; Bulgheresi, Silvia; Egger, Bernhard; Ladurner, Peter; Ott, Jörg A

2012-01-01

308

Bacterial Symbiosis Maintenance in the Asexually Reproducing and Regenerating Flatworm Paracatenula galateia  

PubMed Central

Bacteriocytes set the stage for some of the most intimate interactions between animal and bacterial cells. In all bacteriocyte possessing systems studied so far, de novo formation of bacteriocytes occurs only once in the host development, at the time of symbiosis establishment. Here, we present the free-living symbiotic flatworm Paracatenula galateia and its intracellular, sulfur-oxidizing bacteria as a system with previously undescribed strategies of bacteriocyte formation and bacterial symbiont transmission. Using thymidine analogue S-phase labeling and immunohistochemistry, we show that all somatic cells in adult worms – including bacteriocytes – originate exclusively from aposymbiotic stem cells (neoblasts). The continued bacteriocyte formation from aposymbiotic stem cells in adult animals represents a previously undescribed strategy of symbiosis maintenance and makes P. galateia a unique system to study bacteriocyte differentiation and development. We also provide morphological and immunohistochemical evidence that P. galateia reproduces by asexual fragmentation and regeneration (paratomy) and, thereby, vertically transmits numerous symbiont-containing bacteriocytes to its asexual progeny. Our data support the earlier reported hypothesis that the symbiont population is subjected to reduced bottleneck effects. This would justify both the codiversification between Paracatenula hosts and their Candidatus Riegeria symbionts, and the slow evolutionary rates observed for several symbiont genes. PMID:22509347

Dirks, Ulrich; Gruber-Vodicka, Harald R.; Leisch, Nikolaus; Bulgheresi, Silvia; Egger, Bernhard; Ladurner, Peter; Ott, Jorg A.

2012-01-01

309

Effects of nano-TiO? on the agronomically-relevant Rhizobium-legume symbiosis.  

PubMed

The impact of nano-TiO? on Rhizobium-legume symbiosis was studied using garden peas and the compatible bacterial partner Rhizobium leguminosarum bv. viciae 3841. Exposure to nano-TiO? did not affect the germination of peas grown aseptically, nor did it impact the gross root structure. However, nano-TiO? exposure did impact plant development by decreasing the number of secondary lateral roots. Cultured R. leguminosarum bv. viciae 3841 was also impacted by exposure to nano-TiO?, resulting in morphological changes to the bacterial cells. Moreover, the interaction between these two organisms was disrupted by nano-TiO? exposure, such that root nodule development and the subsequent onset of nitrogen fixation were delayed. Further, the polysaccharide composition of the walls of infected cells of nodules was altered, suggesting that the exposure induced a systemic response in host plants. Therefore, nano-TiO? contamination in the environment is potentially hazardous to the Rhizobium-legume symbiosis system. PMID:23933452

Fan, Ruimei; Huang, Yu Chu; Grusak, Michael A; Huang, C P; Sherrier, D Janine

2014-01-01

310

Mechanisms underlying beneficial plant-fungus interactions in mycorrhizal symbiosis  

Microsoft Academic Search

Mycorrhizal fungi are a heterogeneous group of diverse fungal taxa, associated with the roots of over 90% of all plant species. Recently, state-of-the-art molecular and genetic tools, coupled to high-throughput sequencing and advanced microscopy, have led to the genome and transcriptome analysis of several symbionts. Signalling pathways between plants and fungi have now been described and the identification of several

Paola Bonfante; Andrea Genre

2010-01-01

311

Designing for human-robot symbiosis  

Microsoft Academic Search

For the past ten years, the Intelligent Robotics Laboratory (IRL) at Vanderbilt University has been developing service robots that interact naturally, closely and safely with human beings. Two main issues for research have arisen from this prior work. The first is how to achieve a high level of interaction between the human and robot. The result has been the philosophy

D. M. Wilkes; A. Alford; M. E. Cambron; T. E. Rogers; R. A. Peters II; K. Kawamura

1999-01-01

312

Trophic interactions in a high arctic snow goose colony.  

PubMed

We examined the role of trophic interactions in structuring a high arctic tundra community characterized by a large breeding colony of greater snow geese (Chen caerulescens atlantica). According to the exploitation ecosystem hypothesis of Oksanen et al. (1981), food chains are controlled by top-down interactions. However, because the arctic primary productivity is low, herbivore populations are too small to support functional predator populations and these communities should thus be dominated by the plant/ herbivore trophic-level interaction. Since 1990, we have been monitoring annual abundance and productivity of geese, the impact of goose grazing, predator abundance (mostly arctic foxes, Alopex lagopus) and the abundance of lemmings, the other significant herbivore in this community, on Bylot Island, Nunavut, Canada. Goose grazing consistently removed a significant proportion of the standing crop (?40%) in tundra wetlands every year. Grazing changed plant community composition and reduced the production of grasses and sedges to a low-level equilibrium compared to the situation where the presence of geese had been removed. Lemming cyclic fluctuations were strong and affected fox reproduction. Fox predation on goose eggs was severe and generated marked annual variation in goose productivity. Predation intensity on geese was closely related to the lemming cycle, a consequence of an indirect interaction between lemming and geese via shared predators. We conclude that, contrary to the exploitation ecosystem hypothesis, both the plant/herbivore and predator/prey interactions are significant in this arctic community. PMID:21680492

Gauthier, Gilles; Bêty, Joël; Giroux, Jean-François; Rochefort, Line

2004-04-01

313

Root endophyte symbiosis in vitro between the ectomycorrhizal basidiomycete Tricholoma matsutake and the arbuscular mycorrhizal plant Prunus speciosa.  

PubMed

We previously reported that Tricholoma matsutake and Tricholoma fulvocastaneum, ectomycorrhizal basidiomycetes that associate with Pinaceae and Fagaceae, respectively, in the Northern Hemisphere, could interact in vitro as a root endophyte of somatic plants of Cedrela odorata (Meliaceae), which naturally harbors arbuscular mycorrhizal fungi in South America, to form a characteristic rhizospheric colony or "shiro". We questioned whether this phenomenon could have occurred because of plant-microbe interactions between geographically separated species that never encounter one another in nature. In the present study, we document that these fungi formed root endophyte interactions and shiro within 140 days of inoculation with somatic plants of Prunus speciosa (=Cerasus speciosa, Rosaceae), a wild cherry tree that naturally harbors arbuscular mycorrhizal fungi in Japan. Compared with C. odorata, infected P. speciosa plants had less mycelial sheath surrounding the exodermis, and the older the roots, especially main roots, the more hyphae penetrated. In addition, a large number of juvenile roots were not associated with hyphae. We concluded that such root endophyte interactions were not events isolated to the interactions between exotic plants and microbes but could occur generally in vitro. Our pure culture system with a somatic plant allowed these fungi to express symbiosis-related phenotypes that varied with the plant host; these traits are innately programmed but suppressed in nature and could be useful in genetic analyses of plant-fungal symbiosis. PMID:24158697

Murata, Hitoshi; Yamada, Akiyoshi; Yokota, Satoru; Maruyama, Tsuyoshi; Endo, Naoki; Yamamoto, Kohei; Ohira, Tatsuro; Neda, Hitoshi

2014-05-01

314

Modulation of Aquaporin Genes by the Arbuscular Mycorrhizal Symbiosis in Relation to Osmotic Stress Tolerance  

Microsoft Academic Search

\\u000a This chapter summarizes the current information regarding alteration of aquaporin-encoding genes by the arbuscular mycorrhizal\\u000a (AM) symbiosis, and the relation between the modulation of aquaporin genes and the enhanced tolerance to osmotic stresses\\u000a conferred by the AM symbiosis. The results obtained so far show that the effects of the symbiosis on PIP gene expression depends on the intrinsic properties of

Juan Manuel Ruiz-Lozano; Ricardo Aroca

315

Nuclear energy and waste management – pyroprocess for system symbiosis  

Microsoft Academic Search

The actinide management has become a key issue in nuclear energy. Recovering and fissioning transuranium elements reduce the long-term proliferation risks and the environmental burden. The better way of waste management will be made by system symbiosis: a combination of light-water reactor and fast reactor and\\/or accelerator-driven transmutation system should be sought. The new recycling technology should be able to

Toru Ogawa; Kazuo Minato; Yoshihiro Okamoto; Kenji Nishihara

2007-01-01

316

Evolution of mutualistic symbiosis: A differential equation model  

Microsoft Academic Search

In geological history, rapid speciation, called adaptive radiation, has occurred repeatedly. The origins of such newly developing\\u000a taxa often evolved from the symbiosis of different species. Mutualistic symbioses are generally considered to evolve from\\u000a parasitic relationships. As well as the previous model of host population with discrete generations, a differential equation\\u000a model of host population with overlapping generations shows that

Norio Yamamura

1996-01-01

317

The Winnowing: Establishing the Squid-Vibrio Symbiosis  

NSDL National Science Digital Library

This Nature Reviews Microbiology article examines the symbiosis between the squid Euprymna scolopes and its luminous bacterial symbiont, Vibrio fischeri. Using image-rich illustrations, it depicts the progression of light-organ colonization as a series of steps and discusses the advent of genomic approaches used to study this model system. A subscription is required to access the full-text version of this article.

Nyholm, Spencer V.; Mcfall-Ngai, Margaret; Microbiology, Nature R.

318

Host plant peptides elicit a transcriptional response to control the Sinorhizobium meliloti cell cycle during symbiosis  

E-print Network

The ?-proteobacterium Sinorhizobium meliloti establishes a chronic intracellular infection during the symbiosis with its legume hosts. Within specialized host cells, S. meliloti differentiates into highly polyploid, enlarged ...

Penterman, Jon

319

Coral fluorescence and symbiosis : photoacclimation, thermal shock, life history changes, and implications for reef monitoring.  

E-print Network

??Coral reefs ecosystems are diverse, productive and globally threatened. Corals have endosymbiotic dinoflagellates, which provide important nutrition. This symbiosis depends on a precarious balance of… (more)

Roth, Melissa Susan

2010-01-01

320

Coral fluorescence and symbiosis| Photoacclimation, thermal shock, life history changes, and implications for reef monitoring.  

E-print Network

?? Coral reefs ecosystems are diverse, productive and globally threatened. Corals have endosymbiotic dinoflagellates, which provide important nutrition. This symbiosis depends on a precarious balance… (more)

Roth, Melissa Susan

2010-01-01

321

Quantitative assessment of urban and industrial symbiosis in Kawasaki, Japan.  

PubMed

Colocated firms can achieve environmental benefit and competitive advantage from exchanging physical resources (known as industrial symbiosis) with each other or with residential areas (referenced here as urban symbiosis). Past research illustrated that economic and environmental benefits appear self-evident, although detailed quantification has only been attempted of symbioses for energy and water utilities. This article provides a complimentary case studyfor Kawasaki, Japan. The 14 documented symbioses connect steel, cement, chemical, and paperfirms and their spin-off recycling businesses. Seven key material exchanges divert annually at least 565 000 tons of waste from incineration or landfill. Four of these collectively present an estimated economic opportunity of 13.3 billion JPY (approximately 130 million USD) annually. Five symbioses involve utilization of byproduct and two sharing of utilities. The others are traditional or new recycling industries that do not specifically benefit from geographic proximity. The synergistic effect of urban and industrial symbiosis is unique. The legislative framework for a recycling-oriented society has contributed to realization of the symbioses, as has the availability of government subsidies through the Eco-Town program. PMID:19350890

Van Berkel, Rene; Fujita, Tsuyoshi; Hashimoto, Shizuka; Fujii, Minoru

2009-03-01

322

Zooxanthellar symbiosis in planula larvae of the coral Pocillopora damicornis  

PubMed Central

We characterized the planular-zooxanthellae symbiosis of the coral Pocillopora damicornis using criteria that are familiar in studies on corals. Similar to adult corals, planulae exhibited photoacclimation, as changes in symbiont chlorophyll a (chl a); changes in the light-saturation constant for photosynthesis (Ik); and, at insufficient light, fewer zooxanthellae, decreased respiration, increased weight loss, and increased sensitivity to photoinhibition. Numbers of zooxanthellae in newly-released planulae varied by at least three-fold within broods. Planulae with low versus high numbers of zooxanthellae (termed pale versus dark planulae, respectively) did not differ in symbiont chl-a content, Ik, or biomass-specific rate of dark respiration. Pale planulae had lower rates of photosynthesis, but this difference vanished after three weeks, when zooxanthellar numbers increased by 225% in pale planulae and by 31% in dark planulae. Numbers of zooxanthellae also increased significantly in planulae cultured in ammonium-enriched seawater; ammonium also apparently prevented weight loss and induced settlement. Approximately 70% of photosynthetically-fixed carbon (labeled using 14C) apparently was translocated from the zooxanthellae to their host. A comparison of planulae cultured at 0.3% versus 11% sunlight suggested that photosynthesis provided ~ 31% of the energy utilized by the latter. Overall, we conclude that the physiology of symbiosis in planulae of P. damicornis is broadly similar to symbiosis physiology in adult corals. PMID:20526380

Gaither, Michelle R.; Rowan, Rob

2010-01-01

323

Symbiosis between microorganisms from kombucha and kefir: Potential significance to the enhancement of kombucha function.  

PubMed

Gluconacetobacter sp. A4 (G. sp. A4), which had strong ability to produce d-saccharic acid 1, 4 lactone (DSL), was the key functional bacteria isolated from the kombucha preserved. This paper investigated the interaction between G. sp. A4 and ten different strains of lactic acid bacteria (LAB) obtained from kefir. The result suggested that the LAB promoted DSL production of G. sp. A4 to different extents, ranging from 4.86% to 86.70%. Symbiosis between G. sp. A4 and LAB was studied. LAB's metabolites, xylitol, and acetic acid, were utilized by G. sp. A4, and it promoted the growth of G. sp. A4 and yield of DSL. Therefore, in developing starter cultures for kombucha fermentation process, a mixed flora of LAB and G. sp. A4 would be the optimal combination. PMID:18810658

Yang, Zhiwei; Zhou, Feng; Ji, Baoping; Li, Bo; Luo, Yangchao; Yang, Li; Li, Tao

2010-01-01

324

Electronic copy available at: http://ssrn.com/abstract=2014754 Joshua M. Pearce, "Industrial Symbiosis for Very Large Scale Photovoltaic  

E-print Network

Symbiosis for Very Large Scale Photovoltaic Manufacturing", Renewable Energy 33, pp. 11011108, 2008. http://dx.doi.org/10.1016/j.renene.2007.07.002 Industrial Symbiosis of Very Large Scale Photovoltaic Manufacturing energy demands. This article explores utilizing industrial symbiosis to obtain economies of scale

Paris-Sud XI, Université de

325

3.12 Competition models, Mutualism or Symbiosis The general n -species competition model is decribed by the following systems  

E-print Network

§3.12 Competition models, Mutualism or Symbiosis The general n -species competition model condition on the left (right) hand of converges to ),0( 2K ))0,(( 1K . Mutualism or Symbiosis or symbiosis often plays the crucial role in promoting and #12;even maintaining such species; plant and seed

Hsu, Sze-Bi

326

Observations on Physiology and Symbiosis of the Large Benthic Foraminiferan Operculina Ammonoides from the Gulf of Eilat  

E-print Network

Observations on Physiology and Symbiosis of the Large Benthic Foraminiferan Operculina Ammonoides. Their symbiosis, calcification physiology, and ecological response to environmental changes are poorly understood that calcification is increasing in fed individuals. These data suggest that the symbiosis in LBF is quite different

Simon, Emmanuel

327

The nature of the symbiosis between Indo-Pacific anemone fishes and sea anemones  

Microsoft Academic Search

Under the general heading of symbiosis, defined originally to mean a “living together” of two dissimilar species, exist the sub-categories of mutualism (where both partners benefit), commensalism (where one partner benefits and the other is neutral) and parasitism (where one partner benefits and the other is harmed). The sea anemone-fish (mainly of the genus Amphiprion) symbiosis has generally been considered

R. N. Mariscal

1970-01-01

328

Bacterial Bioluminescence Regulates Expression of a Host Cryptochrome Gene in the Squid-Vibrio Symbiosis  

E-print Network

-Vibrio Symbiosis Elizabeth A. C. Heath-Heckman,a Suzanne M. Peyer,a Cheryl A. Whistler,b Michael A. Apicella, Chapel Hill, North Carolina, USAd ABSTRACT The symbiosis between the squid Euprymna scolopes and its affect host transcriptional rhythms. We identified two transcripts in host tissues (E. scolopes cry1

McFall-Ngai, Margaret

329

Expression Islands Clustered on the Symbiosis Island of the Mesorhizobium loti Genome  

Microsoft Academic Search

Rhizobia are symbiotic nitrogen-fixing soil bacteria that are associated with host legumes. The establishment of rhizobial symbiosis requires signal exchanges between partners in microaerobic environments that result in mutualism for the two partners. We developed a macroarray for Mesorhizobium loti MAFF303099, a microsym- biont of the model legume Lotus japonicus, and monitored the transcriptional dynamics of the bacterium during symbiosis,

Toshiki Uchiumi; Takuji Ohwada; Manabu Itakura; Hisayuki Mitsui; Noriyuki Nukui; Pramod Dawadi; Takakazu Kaneko; Satoshi Tabata; Tadashi Yokoyama; Kouhei Tejima; Kazuhiko Saeki; Hirofumi Omori; Makoto Hayashi; Takaki Maekawa; Rutchadaporn Sriprang; Yoshikatsu Murooka; Shigeyuki Tajima; Kenshiro Simomura; Mika Nomura; Akihiro Suzuki; Yoshikazu Shimoda; Kouki Sioya; Mikiko Abe; Kiwamu Minamisawa

2004-01-01

330

PRESENCE AND DISTRIBUTION OF FUNGAL SYMBIOSIS IN CHEILANTHES FEEI AND CHEILANTHES LANOSA IN SOUTHEASTERN  

E-print Network

TITLE PAGE PRESENCE AND DISTRIBUTION OF FUNGAL SYMBIOSIS IN CHEILANTHES FEEI AND CHEILANTHES LANOSA University PRESENCE AND DISTRIBUTION OF FUNGAL SYMBIOSIS IN CHEILANTHES FEEI AND CHEILANTHES LANOSA #12;ABSTRACT Cheilanthes feei (Polypodiaceae) is a xerophytic fern that grows exclusively on dry

Swatzell, Lucinda

331

Soil phosphorus heterogeneity and mycorrhizal symbiosis regulate plant intra-specific competition and size distribution.  

PubMed

We investigated the interactive effects of soil phosphorus (P) heterogeneity, plant density and mycorrhizal symbiosis on plant growth and size variability of Trifolium subterraneum. We set up mesocosms (trays 49×49 cm and 12 cm deep) with the same amount of available P, but distributed either homogeneously or heterogeneously, in randomly arranged cells (7×7 cm each) with high or low available P. The trays were planted with either 1 or 4 seedlings of T. subterraneum per cell. Half of the trays were inoculated with spores of the mycorrhizal fungus Gigaspora margarita. We harvested the plants when leaves just started to overlap, 8 weeks after planting. Plants growing in high P cells had the lowest percentage infection, but the highest mean shoot and root biomass and root length. The mean size of the plants in each cell was determined mainly by local P concentration. However, in plants growing in high density, low P cells, ca. 20% of the variability in plant biomass was explained by the number of adjacent cells with high P. Patchy trays had the highest total shoot biomass, independently of mycorrhizal infection or plant density. Inoculated trays (M) had higher total shoot biomass and relative competition intensity (measured as reduction in plant biomass due to increased density) than non-inoculated trays (NM). Plant density reduced the plant response to mycorrhizal infection, and its effect was independent of P distribution. All populations growing in patchy trays, and low density mycorrhizal ones, had the highest plant-size inequality, presumably because patchy distribution of P and mycorrhizal infection increased competitive asymmetry. We conclude that mycorrhizal symbiosis has the potential to strongly influence plant population structure when soil nutrient distribution is heterogeneous because it promotes pre-emption of limiting resources. PMID:24599369

Facelli, Evelina; Facelli, José M

2002-09-01

332

Stellar Pulsations and Stellar Evolution: Conflict, Cohabitation, or Symbiosis?  

NASA Astrophysics Data System (ADS)

While the analysis of stellar pulsations allows the determination of current properties of a star, stellar evolution models connect it with its previous history. In many cases results from both methods do not agree. In this review some classical and current cases of disagreement are presented. In some cases these conflicts led to an improvement of the theory of stellar evolution, while in others they still remain unsolved. Some well-known problems of stellar physics are pointed out as well, for which it is hoped that seismology—or in general the analysis of stellar pulsations—will help to resolve them. The limits of this symbiosis will be discussed as well.

Weiss, Achim

333

Stars and Symbiosis: MicroRNA- and MicroRNA*-Mediated Transcript Cleavage Involved in Arbuscular Mycorrhizal Symbiosis1[W][OA  

PubMed Central

The majority of plants are able to form the arbuscular mycorrhizal (AM) symbiosis in association with AM fungi. During symbiosis development, plant cells undergo a complex reprogramming resulting in profound morphological and physiological changes. MicroRNAs (miRNAs) are important components of the regulatory network of plant cells. To unravel the impact of miRNAs and miRNA-mediated mRNA cleavage on root cell reprogramming during AM symbiosis, we carried out high-throughput (Illumina) sequencing of small RNAs and degradome tags of Medicago truncatula roots. This led to the annotation of 243 novel miRNAs. An increased accumulation of several novel and conserved miRNAs in mycorrhizal roots suggest a role of these miRNAs during AM symbiosis. The degradome analysis led to the identification of 185 root transcripts as mature miRNA and also miRNA*-mediated mRNA cleavage targets. Several of the identified miRNA targets are known to be involved in root symbioses. In summary, the increased accumulation of specific miRNAs and the miRNA-mediated cleavage of symbiosis-relevant genes indicate that miRNAs are an important part of the regulatory network leading to symbiosis development. PMID:21571671

Devers, Emanuel A.; Branscheid, Anja; May, Patrick; Krajinski, Franziska

2011-01-01

334

High phosphate reduces host ability to develop arbuscular mycorrhizal symbiosis without affecting root calcium spiking responses to the fungus.  

PubMed

The arbuscular mycorrhizal symbiosis associates soil fungi with the roots of the majority of plants species and represents a major source of soil phosphorus acquisition. Mycorrhizal interactions begin with an exchange of molecular signals between the two partners. A root signaling pathway is recruited, for which the perception of fungal signals triggers oscillations of intracellular calcium concentration. High phosphate availability is known to inhibit the establishment and/or persistence of this symbiosis, thereby favoring the direct, non-symbiotic uptake of phosphorus by the root system. In this study, Medicago truncatula plants were used to investigate the effects of phosphate supply on the early stages of the interaction. When plants were supplied with high phosphate fungal attachment to the roots was drastically reduced. An experimental system was designed to individually study the effects of phosphate supply on the fungus, on the roots, and on root exudates. These experiments revealed that the most important effects of high phosphate supply were on the roots themselves, which became unable to host mycorrhizal fungi even when these had been appropriately stimulated. The ability of the roots to perceive their fungal partner was then investigated by monitoring nuclear calcium spiking in response to fungal signals. This response did not appear to be affected by high phosphate supply. In conclusion, high levels of phosphate predominantly impact the plant host, but apparently not in its ability to perceive the fungal partner. PMID:24194742

Balzergue, Coline; Chabaud, Mireille; Barker, David G; Bécard, Guillaume; Rochange, Soizic F

2013-01-01

335

The Santa Barbara Basin is a symbiosis oasis.  

PubMed

It is generally agreed that the origin and initial diversification of Eucarya occurred in the late Archaean or Proterozoic Eons when atmospheric oxygen levels were low and the risk of DNA damage due to ultraviolet radiation was high. Because deep water provides refuge against ultraviolet radiation and early eukaryotes may have been aerotolerant anaerobes, deep-water dysoxic environments are likely settings for primeval eukaryotic diversification. Fossil evidence shows that deep-sea microbial mats, possibly of sulphur bacteria similar to Beggiatoa, existed during that time. Here we report on the eukaryotic community of a modern analogue, the Santa Barbara Basin (California, USA). The Beggiatoa mats of these severely dysoxic and sulphidic sediments support a surprisingly abundant protistan and metazoan meiofaunal community, most members of which harbour prokaryotic symbionts. Many of these taxa are new to science, and both microaerophilic and anaerobic taxa appear to be represented. Compared with nearby aerated sites, the Santa Barbara Basin is a 'symbiosis oasis' offering a new source of organisms for testing symbiosis hypotheses of eukaryogenesis. PMID:10638755

Bernhard, J M; Buck, K R; Farmer, M A; Bowser, S S

2000-01-01

336

Methanotrophic marine molluscan (Bivalvia, Mytilidae) symbiosis: mussels fueled by gas  

SciTech Connect

An undescribed mussel (family Mytilidae), which lives in the vicinity of hydrocarbon seeps in the Gulf of Mexico, consumes methane (the principal component of natural gas) at a high rate. The methane consumption is limited to the gills of these animals and is apparently due to the abundant intracellular bacteria found there. This demonstrates a methane-based symbiosis between an animal and intracellular bacteria. Methane consumption is dependent on the availability of oxygen and is inhibited by acetylene. The consumption of methane by these mussels is associated with a dramatic increase in oxygen consumption and carbon dioxide production. As the methane consumption of the bivalve can exceed its carbide dioxide production, the symbiosis may be able to entirely satisfy its carbon needs from methane uptake. The very light (delta/sup 13/C = -51 to -57 per mil) stable carbon isotope ratios found in this animal support methane (delta/sup 13/C = -45 per mil at this site) as the primary carbon source for both the mussels and their symbionts. 19 references, 2 figures, 1 table.

Childress, J.J.; Fisher, C.R.; Brooks, J.M.; Kennicutt, M.C. II; Bidigare, R.; Anderson, A.E.

1986-09-19

337

Symbiosis as a source of selectable epigenetic variation: taking the heat for the big guy  

PubMed Central

Evolutionary developmental biology is based on the principle that evolution arises from hereditable changes in development. Most of this new work has centred on changes in the regulatory components of the genome. However, recent studies (many of them documented in this volume) have shown that development also includes interactions between the organism and its environment. One area of interest concerns the importance of symbionts for the production of the normal range of phenotypes. Many, if not most, organisms have ‘outsourced’ some of their developmental signals to a set of symbionts that are expected to be acquired during development. Such intimate interactions between species are referred to as codevelopment, the production of a new individual through the coordinated interactions of several genotypically different species. Within the past 2 years, several research programmes have demonstrated that such codevelopmental schemes can be selected. We will focus on symbioses in coral reef cnidarians symbiosis, pea aphids and cactuses, wherein the symbiotic system provides thermotolerance for the composite organism. PMID:20083641

Gilbert, Scott F.; McDonald, Emily; Boyle, Nicole; Buttino, Nicholas; Gyi, Lin; Mai, Mark; Prakash, Neelakantan; Robinson, James

2010-01-01

338

Protocol: using virus-induced gene silencing to study the arbuscular mycorrhizal symbiosis in Pisum sativum  

PubMed Central

Virus-induced gene silencing (VIGS) is an alternative reverse genetics tool for silencing of genes in some plants, which are difficult to transform. The pea early-browning virus (PEBV) has been developed as a VIGS vector and used in pea for functional analysis of several genes. However, the available PEBV-VIGS protocols are inadequate for studying genes involved in the symbiosis with arbuscular mycorrhizal fungi (AMF). Here we describe a PEBV-VIGS protocol suitable for reverse genetics studies in pea of genes involved in the symbiosis with AMF and show its effectiveness in silencing genes involved in the early and late stages of AMF symbiosis. PMID:21156044

2010-01-01

339

Predator-prey relationships in mummichogs ( Fundulus heteroclitus (L.)): Effects of living in a polluted environment  

Microsoft Academic Search

Analysis of prey capture ability of mummichogs, Fundulus heteroclitus (L.) from a mercury-polluted tidal creek compared with conspecifics from an uncontaminated environment showed that the latter captured the prey organism Palaemonetes pugio Holthuis at a significantly faster rate and had significantly lower levels of mercury in their brain tissues. Exposure of uncontaminated fish to conditions similar to those of the

Graeme M. Smith; Judith S. Weis

1997-01-01

340

Nature's Partners: predators, prey & you revising mental models creating mental models  

E-print Network

, the contents of this page are property of Dr. Jane Packard and the Technology Assisted Learning Lab at Texas A&M University. For technical assistance with this page contact theTechnology Assisted Learning Lab at (979) 862

Packard, Jane M.

341

Period Doubling Cascades in a Predator-Prey Model with a Scavenger  

E-print Network

in tritrophic food chains for the Rosenzweig-MacArthur model and constructed organizing centers of overall techniques. Our focus is on Lotka-Volterra predation equations in which the predator benefits from benefits from the presence of other species [13]. For literature on Lotka-Volterra competition models, see

Previte, Joseph P.

342

Increasing isolation reduces predator:prey species richness ratios in aquatic food webs  

Microsoft Academic Search

The number of species that live in a habitat typically declines as that habitat becomes more isolated. However, the influence of habitat isolation on patterns of food web structure, in particular the ratio of predator to prey species richness, is less well understood. We placed aquatic mesocosms at varying distances from ponds that acted as sources of potential colonists; then

Rachel S. Shulman; Jonathan M. Chase

2007-01-01

343

A Mammalian Predator-Prey Imbalance: Grizzly Bear and Wolf Extinction Affect Avian Neotropical Migrants  

Microsoft Academic Search

Because most large, terrestrial mammalian predators have already been lost from more than 95-99% of the contiguous United States and Mexico, many ecological communities are either missing dominant selective forces or have new ones dependent upon humans. Such large-scale manipulations of a key element of most ecosystems offer unique opportunities to investigate how the loss of large carnivores affects communities,

Joel Berger; Peter B. Stacey; Lori Bellis; Matthew P. Johnson

2001-01-01

344

Apes finding ants: Predator-prey dynamics in a chimpanzee habitat in Nigeria.  

PubMed

Some chimpanzee populations prey upon army ants, usually with stick tools. However, how their prey's subterranean nesting and nomadic lifestyle influence the apes' harvesting success is still poorly understood. This is particularly true for chimpanzees (Pan troglodytes ellioti) at Gashaka/Nigeria, which consume army ants (Dorylus rubellus) with much higher frequency than at other sites. We assessed various harvesting and search options theoretically available to the apes. For this, we reconstructed annual consumption patterns from feces and compared the physical characteristics of exploited ant nests with those that were not targeted. Repeated exploitation of a discovered nest is viable only in the short term, as disturbed colonies soon moved to a new site. Moreover, monitoring previously occupied nest cavities is uneconomical, as ants hardly ever re-used them. Thus, the apes have to detect new nests regularly, although colony density is relatively low (1 colony/1.3 ha). Surprisingly, visual search cues seem to be of limited importance because the probability of a nest being exploited was independent of its conspicuousness (presence of excavated soil piles, concealing leaf-litter or vegetation). However, chimpanzees preferentially targeted nests in forests or at the base of food trees, that is, where the apes spend relatively more time and/or where ant colony density is highest. Taken together, our findings suggest that, instead of employing a search strategy based on visual cues or spatial memory, chimpanzee predation on army ants contains a considerable opportunistic element. PMID:24022711

Pascual-Garrido, Alejandra; Umaru, Buba; Allon, Oliver; Sommer, Volker

2013-12-01

345

Predator-prey oscillations, synchronization and pattern formation in ecological systems  

Microsoft Academic Search

Ecological systems and their component biological populations exhibit a broad spectrum of non-equilibrium dynamics ranging from characteristic natural cy-cles to more complex chaotic oscillations [1]. Perhaps the most spectacular example of this dynamic is Ecology's well known hare-lynx cycle. Despite unpredictable population fluctuations from one cycle to the next in the snow-shoe hare (Lepus americanus) and the Canadian lynx (Lynx

Bernd Blasius; Ralf Tonjes

346

Nature's Partners: predators, prey & you revising mental models creating mental models  

E-print Network

of the same display behavior (may be another scene or individual in the same clip). Repeat STEP 2 to fill, and choose one communication display to analyze in more detail in terms of sender/receiver. Write your Folk Psychology Questions about beliefs, emotions, desires of the animal Proximate Questions about

Packard, Jane M.

347

Implicit - symplectic partitioned (IMSP) Runge-Kutta schemes for predator-prey dynamics  

NASA Astrophysics Data System (ADS)

In the study of the effects of habitat fragmentation on biodiversity the role of spatial processes reveals of great interest since both the variation of size of the domains as well as their heterogeneity largely affects the dynamics of species. In order to begin a preliminary study about the effects of habitat fragmentation on wolf - wild boar pair populating the Italian "Alta Murgia" Natura 2000 site, object of interest for FP7 project BIOSOS, (BIOdiversity multi-SOurce Monitoring System: from Space TO Species), spatially explicit models described by reaction-diffusion partial differential equations are considered. Numerical methods based on partitioned Runge-Kutta schemes which use an implicit scheme for the stiff diffusive term and a partitioned symplectic scheme for the reaction function are here proposed. We are motivated by the classical results about Lotka-Volterra model described by ordinary differential equations to which the spatially explicit model reduces for diffusion coefficients tending to zero: for their accurate solution symplectic schemes have to be used for an optimal long run preservation of the dynamics invariant. Moreover, for models based on logistic growth and Holling type II functional predator response we verify the better performance of our schemes when compared with classical implicit-explicit (IMEX) schemes on chaotic dynamics given in literature.

Diele, F.; Marangi, C.; Ragni, S.

2012-09-01

348

Population dynamics and predator-prey relationships of the Carmen Mountains white-tailed deer  

E-print Network

. Jack M. Inglis Five parameters were used to evaluate the status of the Carmen Mo otal a white-tailed deer (odocoi leuu ~vir i ia ua carmioit, Goldmao and Kellogg) in Big Bend National Park during 1971 and 1972. These included density, estimated... total numbers, relative abundance between years, sex ratios and predation pressure. Hahn cruise lines and pellet group transects were employed to estimate density in both sotol grass- land and woodland vegetative types of the Chisos Mountains. Cruise...

Atkinson, Don Eugene

2012-06-07

349

A jump-growth model for predator-prey dynamics: derivation and application to marine ecosystems.  

PubMed

This paper investigates the dynamics of biomass in a marine ecosystem. A stochastic process is defined in which organisms undergo jumps in body size as they catch and eat smaller organisms. Using a systematic expansion of the master equation, we derive a deterministic equation for the macroscopic dynamics, which we call the deterministic jump-growth equation, and a linear Fokker-Planck equation for the stochastic fluctuations. The McKendrick-von Foerster equation, used in previous studies, is shown to be a first-order approximation, appropriate in equilibrium systems where predators are much larger than their prey. The model has a power-law steady state consistent with the approximate constancy of mass density in logarithmic intervals of body mass often observed in marine ecosystems. The behaviours of the stochastic process, the deterministic jump-growth equation, and the McKendrick-von Foerster equation are compared using numerical methods. The numerical analysis shows two classes of attractors: steady states and travelling waves. PMID:20058090

Datta, Samik; Delius, Gustav W; Law, Richard

2010-08-01

350

Evolution towards oscillation or stability in a predator-prey system  

PubMed Central

We studied a prey–predator system in which both species evolve. We discuss here the conditions that result in coevolution towards a stable equilibrium or towards oscillations. First, we show that a stable equilibrium or population oscillations with small amplitude is likely to occur if the prey's (host's) defence is effective when compared with the predator's (parasite's) attacking ability at equilibrium, whereas large-amplitude oscillations are likely if the predator's (parasite's) attacking ability exceeds the prey's (host's) defensive ability. Second, a stable equilibrium is more likely if the prey's defensive trait evolves faster than the predator's attack trait, whereas population oscillations are likely if the predator's trait evolves faster than that of the prey. Third, when the adaptation rates of both species are similar, the amplitude of the fluctuations in their abundances is small when the adaptation rate is either very slow or very fast, but at an intermediate rate of adaptation the fluctuations have a large amplitude. We also show the case in which the prey's abundance and trait fluctuate greatly, while those of the predator remain almost unchanged. Our results predict that populations and traits in host–parasite systems are more likely than those in prey–predator systems to show large-amplitude oscillations. PMID:20504808

Mougi, Akihiko; Iwasa, Yoh

2010-01-01

351

Hatching in dabbling ducks and emergence in chironomids: a case of predator–prey synchrony?  

Microsoft Academic Search

It has been hypothesized that dabbling ducks (Anas spp.) time breeding to coincide with annual regional peaks in emerging dipterans, especially Chironomidae, which are important\\u000a prey for newly hatched ducklings. However, this hypothesis has never been evaluated in a replicated lake-level study, including\\u000a year effects in emergence patterns. We collected duck and invertebrate data from 12 lakes during the nesting

Lisa Dessborn; Johan Elmberg; Petri Nummi; Hannu Pöysä; Kjell Sjöberg

2009-01-01

352

Predator-prey role reversals, juvenile experience and adult antipredator behaviour  

PubMed Central

Although biologists routinely label animals as predators and prey, the ecological role of individuals is often far from clear. There are many examples of role reversals in predators and prey, where adult prey attack vulnerable young predators. This implies that juvenile prey that escape from predation and become adult can kill juvenile predators. We show that such an exposure of juvenile prey to adult predators results in behavioural changes later in life: after becoming adult, these prey killed juvenile predators at a faster rate than prey that had not been exposed. The attacks were specifically aimed at predators of the species to which they had been exposed. This suggests that prey recognize the species of predator to which they were exposed during their juvenile stage. Our results show that juvenile experience affects adult behaviour after a role reversal. PMID:23061011

Choh, Yasuyuki; Ignacio, Maira; Sabelis, Maurice W.; Janssen, Arne

2012-01-01

353

SUPPORTING ONLINE MATERIAL Cyclic dynamics in a simple vertebrate predator-prey community  

E-print Network

, the main alternate prey are birds (ptarmigan, waders and passerines) for the snowy owl, small birds, fishes at snowmelt (N') based on the density of winter nests for 1988-2002 and on direct live-trapping for 1998 to be looked for since only the male snowy owl hunts (and feeds the female) while the skuas take turns

Helsinki, University of

354

Sedentary snakes and gullible geckos: predator–prey coevolution in nocturnal rock-dwelling reptiles  

Microsoft Academic Search

We investigated (1) the importance of chemical cues for predator detection by the nocturnal, rock-dwelling velvet gecko,Oedura lesueurii, and (2) how the lizards’ responses to snake odour may have exerted selection on the foraging behaviours of a nocturnal elapid snake. This snake species (broadheaded snake,Hoplocephalus bungaroides) feeds primarily on velvet geckos, and does so by means of a distinctive foraging

SHARON DOWNES; RICHARD SHINE

1998-01-01

355

Predator-prey size relationships in an African large-mammal food web.  

PubMed

1. Size relationships are central in structuring trophic linkages within food webs, leading to suggestions that the dietary niche of smaller carnivores is nested within that of larger species. However, past analyses have not taken into account the differing selection shown by carnivores for specific size ranges of prey, nor the extent to which the greater carcass mass of larger prey outweighs the greater numerical representation of smaller prey species in the predator diet. Furthermore, the top-down impact that predation has on prey abundance cannot be assessed simply in terms of the number of predator species involved. 2. Records of found carcasses and cause of death assembled over 46 years in the Kruger National Park, South Africa, corrected for under-recording of smaller species, enabled a definitive assessment of size relationships between large mammalian carnivores and their ungulate prey. Five carnivore species were considered, including lion (Panthera leo), leopard (Panthera pardus), cheetah (Acinonyx jubatus), African wild dog (Lycaon pictus) and spotted hyena (Crocuta crocuta), and 22 herbivore prey species larger than 10 kg in adult body mass. 3. These carnivores selectively favoured prey species approximately half to twice their mass, within a total prey size range from an order of magnitude below to an order of magnitude above the body mass of the predator. The three smallest carnivores, i.e. leopard, cheetah and wild dog, showed high similarity in prey species favoured. Despite overlap in prey size range, each carnivore showed a distinct dietary preference. 4. Almost all mortality was through the agency of a predator for ungulate species up to the size of a giraffe (800-1200 kg). Ungulates larger than twice the mass of the predator contributed substantially to the dietary intake of lions, despite the low proportional mortality inflicted by predation on these species. Only for megaherbivores substantially exceeding 1000 kg in adult body mass did predation become a negligible cause of mortality. 5. Hence, the relative size of predators and prey had a pervasive structuring influence on biomass fluxes within this large-mammal food web. Nevertheless, the large carnivore assemblage was dominated overwhelmingly by the largest predator, which contributed the major share of animals killed across a wide size range. PMID:18177336

Owen-Smith, Norman; Mills, M G L

2008-01-01

356

Predator-Prey Relations in Large South Dakota Job 1: Seasonal Walleye and Smallmouth Bass Diets  

E-print Network

Department of Game, Fish and Parks. #12;iii ABSTRACT Walleye Sander vitreus are the most popular fish among, which consumed a wide range of shad sizes. Smallmouth bass consumed Sander spp. in some months

357

Hydrologic drivers and controls of stream biofilm-grazer interactions  

NASA Astrophysics Data System (ADS)

Understanding the dynamics of fluvial ecosystems linked to hydrology is one of the most important challenges of ecohydrology. In fact, streamflow, which chiefly relies on rainfall, climate, land use and geomorphologic properties, plays a fundamental role in sustaining and regulating fluvial ecosystem integrity. To analyze possible implications of hydrological fluctuations on the biofilm-grazer interaction - a major driver for nutrient cycling and metabolism in streams - we experimented with 36 3-m-long flumes. In particular, two distinct discharge treatments (constant and stochastic discharge regimes) coupled with six different light regimes (from natural light conditions to nearly 70% attenuation) have been performed. To complement and analyze the experimental results, a dynamic model, based on the Rosenzweig-MacArthur predator-prey model, is presented. Several relations between the parameters of the aforementioned model and hydrologic and hydraulic properties, such as streamflow, water depth, flow velocity, shear stress, and light availability will be explored to explain ecohydrologic influences on the basic food-web dynamics.

Ceola, S.; Bertuzzo, E.; Mari, L.; Botter, G.; Hödl, I.; Battin, T. J.; Rinaldo, A.

2011-12-01

358

Inter-specific interactions linking predation and scavenging in terrestrial vertebrate assemblages.  

PubMed

Predation and scavenging have been classically understood as independent processes, with predator-prey interactions and scavenger-carrion relationships occurring separately. However, the mere recognition that most predators also scavenge at variable rates, which has been traditionally ignored in food-web and community ecology, leads to a number of emergent interaction routes linking predation and scavenging. The general goal of this review is to draw attention to the main inter-specific interactions connecting predators (particularly, large mammalian carnivores), their live prey (mainly ungulates), vultures and carrion production in terrestrial assemblages of vertebrates. Overall, we report an intricate network of both direct (competition, facilitation) and indirect (hyperpredation, hypopredation) processes, and provide a conceptual framework for the future development of this promising topic in ecological, evolutionary and biodiversity conservation research. The classic view that scavenging does not affect the population dynamics of consumed organisms is questioned, as multiple indirect top-down effects emerge when considering carrion and its facultative consumption by predators as fundamental and dynamic components of food webs. Stimulating although challenging research opportunities arise from the study of the interactions among living and detrital or non-living resource pools in food webs. PMID:24602047

Moleón, Marcos; Sánchez-Zapata, José A; Selva, Nuria; Donázar, José A; Owen-Smith, Norman

2014-11-01

359

Effects of multiple climate change factors on the tall fescue-fungal endophyte symbiosis: infection frequency and tissue chemistry.  

SciTech Connect

Climate change (altered CO{sub 2}, warming, and precipitation) may affect plant-microbial interactions, such as the Lolium arundinaceum-Neotyphodium coenophialum symbiosis, to alter future ecosystem structure and function. To assess this possibility, tall fescue tillers were collected from an existing climate manipulation experiment in a constructed old-field community in Tennessee (USA). Endophyte infection frequency (EIF) was determined, and infected (E+) and uninfected (E-) tillers were analysed for tissue chemistry. The EIF of tall fescue was higher under elevated CO{sub 2} (91% infected) than with ambient CO{sub 2} (81%) but was not affected by warming or precipitation treatments. Within E+ tillers, elevated CO{sub 2} decreased alkaloid concentrations of both ergovaline and loline, by c. 30%; whereas warming increased loline concentrations 28% but had no effect on ergovaline. Independent of endophyte infection, elevated CO{sub 2} reduced concentrations of nitrogen, cellulose, hemicellulose, and lignin. These results suggest that elevated CO{sub 2}, more than changes in temperature or precipitation, may promote this grass-fungal symbiosis, leading to higher EIF in tall fescue in old-field communities. However, as all three climate factors are likely to change in the future, predicting the symbiotic response and resulting ecological consequences may be difficult and dependent on the specific atmospheric and climatic conditions encountered.

Brosi, Glade [University of Kentucky; McCulley, Rebecca L [University of Kentucky; Bush, L P [University of Kentucky; Nelson, Jim A [University of Kentucky; Classen, Aimee T [University of Tennessee, Knoxville (UTK); Norby, Richard J [ORNL

2011-01-01

360

Lipopolysaccharide mutants of Rhizobium meliloti are not defective in symbiosis.  

PubMed Central

Mutants of Rhizobium meliloti selected primarily for bacteriophage resistance fall into 13 groups. Mutants in the four best-characterized groups (class A, lpsB, lpsC, and class D), which map to the rhizobial chromosome, appear to affect lipopolysaccharide (LPS) as judged by the reactivity with monoclonal antibodies and behavior on sodium dodecyl sulfate-polyacrylamide gels of extracted LPS. Mutations in all 13 groups, in an otherwise wild-type genetic background, are Fix+ on alfalfa. This suggests that LPS does not play a major role in symbiosis. Mutations in lpsB, however, are Fix- in one particular genetic background, evidently because of the cumulative effect of several independent background mutations. In addition, an auxotrophic mutation evidently equivalent to Escherichia coli carAB is Fix- on alfalfa. Images PMID:2738026

Clover, R H; Kieber, J; Signer, E R

1989-01-01

361

Lipopolysaccharide mutants of Rhizobium meliloti are not defective in symbiosis  

SciTech Connect

Mutants of Rhizobium meliloti selected primarily for bacteriophage resistance fall into 13 groups. Mutants in the four best-characterized groups (class A, lpsB, lpsC, and class D), which map to the rhizobial chromosome, appear to affect lipopolysaccharide (LPS) as judged by the reactivity with monoclonal antibodies and behavior on sodium dodecyl sulfate-polyacrylamide gels of extracted LPS. Mutations in all 13 groups, in an otherwise wild-type genetic background, are Fix{sup +} on alfalfa. This suggests that LPS does not play a major role in symbiosis. Mutations in lpsB, however, are Fix{sup {minus}} in one particular genetic background, evidently because of the cumulative effect of several independent background mutations. In addition, an auxotrophic mutation evidently equivalent to Escherichia coli carAB is Fix{sup {minus}} on alfalfa.

Clover, R.H.; Kieber, J.; Signer, E.R. (Massachusetts Institute of Technology, Cambridge (USA))

1989-07-01

362

Aspects of narcissism and symbiosis, or, essential neurosis of twins.  

PubMed

Following a brief introduction I address the relationships of twins from five different perspectives: the Intimate Connection, the Mirror Image and Complementarity, Object- and Self-Representation, Self and Object or Rivalry, and Intersubjective Communication. This approach attempts to understand twin relationships and the individual development of twins in terms of their intense mutual dependence, akin to infantile symbiosis, and in terms of narcissism. In their similarity to each other, twins may choose each other as love objects even as they see themselves in the other. That is, a twin may "love what he himself is" or "someone who was once part of himself." This "type of object-choice … must be termed 'narcissistic'" (Freud, 1914, pp. 90, 88). Such "cathexis of an undifferentiated self-object" is considered to be "primary narcissism" (Burstein, 1977, p. 103). Hoffer (1952) describes primary narcissism as "the lack of all qualities discriminating between self and not-self, inside and outside" (p. 33). PMID:22712590

Kahn, Charlotte

2012-06-01

363

Nuclear energy and waste management pyroprocess for system symbiosis  

NASA Astrophysics Data System (ADS)

The actinide management has become a key issue in nuclear energy. Recovering and fissioning transuranium elements reduce the long-term proliferation risks and the environmental burden. The better way of waste management will be made by system symbiosis: a combination of light-water reactor and fast reactor and/or accelerator-driven transmutation system should be sought. The new recycling technology should be able to achieve good economy with smaller plants, which can process fuels from different types of reactors on a common technical basis. Ease in handling the higher heat load of transuranium nuclides is also important. Pyroprocesses with the use of molten salts are regarded as the strong candidate for such recycling technology. In JAEA, the first laboratory for the high-temperature chemistry of Am and Cm has been established. The fundamental data will be combined with the computer code for predicting the molten-salts electrolytic processes.

Ogawa, Toru; Minato, Kazuo; Okamoto, Yoshihiro; Nishihara, Kenji

2007-01-01

364

Differential effects of rare specific flavonoids on compatible and incompatible strains in the Myrica gale-Frankia actinorhizal symbiosis.  

PubMed

Plant secondary metabolites, and specifically phenolics, play important roles when plants interact with their environment and can act as weapons or positive signals during biotic interactions. One such interaction, the establishment of mutualistic nitrogen-fixing symbioses, typically involves phenolic-based recognition mechanisms between host plants and bacterial symbionts during the early stages of interaction. While these mechanisms are well studied in the rhizobia-legume symbiosis, little is known about the role of plant phenolics in the symbiosis between actinorhizal plants and Frankia genus strains. In this study, the responsiveness of Frankia strains to plant phenolics was correlated with their symbiotic compatibility. We used Myrica gale, a host species with narrow symbiont specificity, and a set of compatible and noncompatible Frankia strains. M. gale fruit exudate phenolics were extracted, and 8 dominant molecules were purified and identified as flavonoids by high-resolution spectroscopic techniques. Total fruit exudates, along with two purified dihydrochalcone molecules, induced modifications of bacterial growth and nitrogen fixation according to the symbiotic specificity of strains, enhancing compatible strains and inhibiting incompatible ones. Candidate genes involved in these effects were identified by a global transcriptomic approach using ACN14a strain whole-genome microarrays. Fruit exudates induced differential expression of 22 genes involved mostly in oxidative stress response and drug resistance, along with the overexpression of a whiB transcriptional regulator. This work provides evidence for the involvement of plant secondary metabolites in determining symbiotic specificity and expands our understanding of the mechanisms, leading to the establishment of actinorhizal symbioses. PMID:20190089

Popovici, Jean; Comte, Gilles; Bagnarol, Emilie; Alloisio, Nicole; Fournier, Pascale; Bellvert, Floriant; Bertrand, Cédric; Fernandez, Maria P

2010-04-01

365

Differential Effects of Rare Specific Flavonoids on Compatible and Incompatible Strains in the Myrica gale-Frankia Actinorhizal Symbiosis? †  

PubMed Central

Plant secondary metabolites, and specifically phenolics, play important roles when plants interact with their environment and can act as weapons or positive signals during biotic interactions. One such interaction, the establishment of mutualistic nitrogen-fixing symbioses, typically involves phenolic-based recognition mechanisms between host plants and bacterial symbionts during the early stages of interaction. While these mechanisms are well studied in the rhizobia-legume symbiosis, little is known about the role of plant phenolics in the symbiosis between actinorhizal plants and Frankia genus strains. In this study, the responsiveness of Frankia strains to plant phenolics was correlated with their symbiotic compatibility. We used Myrica gale, a host species with narrow symbiont specificity, and a set of compatible and noncompatible Frankia strains. M. gale fruit exudate phenolics were extracted, and 8 dominant molecules were purified and identified as flavonoids by high-resolution spectroscopic techniques. Total fruit exudates, along with two purified dihydrochalcone molecules, induced modifications of bacterial growth and nitrogen fixation according to the symbiotic specificity of strains, enhancing compatible strains and inhibiting incompatible ones. Candidate genes involved in these effects were identified by a global transcriptomic approach using ACN14a strain whole-genome microarrays. Fruit exudates induced differential expression of 22 genes involved mostly in oxidative stress response and drug resistance, along with the overexpression of a whiB transcriptional regulator. This work provides evidence for the involvement of plant secondary metabolites in determining symbiotic specificity and expands our understanding of the mechanisms, leading to the establishment of actinorhizal symbioses. PMID:20190089

Popovici, Jean; Comte, Gilles; Bagnarol, Emilie; Alloisio, Nicole; Fournier, Pascale; Bellvert, Floriant; Bertrand, Cedric; Fernandez, Maria P.

2010-01-01

366

Industrial symbiosis and the successional city : adapting exchange networks to energy constraints  

E-print Network

Industrial ecology offers models for hybridizing technology and natural processes, human desires and the capacities of ecosystems in an effort to reconcile the expanding conflicts among them. Industrial symbiosis applies ...

Terway, Timothy M. (Timothy Michael)

2007-01-01

367

Unveiling in situ interactions between marine protists and bacteria through single cell sequencing.  

PubMed

Heterotrophic protists are a highly diverse and biogeochemically significant component of marine ecosystems, yet little is known about their species-specific prey preferences and symbiotic interactions in situ. Here we demonstrate how these previously unresolved questions can be addressed by sequencing the eukaryote and bacterial SSU rRNA genes from individual, uncultured protist cells collected from their natural marine environment and sorted by flow cytometry. We detected Pelagibacter ubique in association with a MAST-4 protist, an actinobacterium in association with a chrysophyte and three bacteroidetes in association with diverse protist groups. The presence of identical phylotypes among the putative prey and the free bacterioplankton in the same sample provides evidence for predator-prey interactions. Our results also suggest a discovery of novel symbionts, distantly related to Rickettsiales and the candidate divisions ZB3 and TG2, associated with Cercozoa and Chrysophyta cells. This study demonstrates the power of single cell sequencing to untangle ecological interactions between uncultured protists and prokaryotes. PMID:21938022

Martinez-Garcia, Manuel; Brazel, David; Poulton, Nicole J; Swan, Brandon K; Gomez, Monica Lluesma; Masland, Dashiell; Sieracki, Michael E; Stepanauskas, Ramunas

2012-03-01

368

Interactions among phytophagous mites, and introduced and naturally occurring predatory mites, on strawberry in the UK.  

PubMed

In choice test experiments on strawberry leaf disc arenas the phytoseiid mites Neoseiulus californicus and N. cucumeris were more effective than Typhlodromus pyri as predators of the phytophagous mites Tetranychus urticae and Phytonemus pallidus. There were no preferences shown for either prey by any of these predators. In multiple predator leaf disc experiments both Phytoseiulus persimilis and N. cucumeris significantly reduced numbers of T. urticae eggs and active stages; this effect was seen when the two species were present alone or in combination with other predator species. Neoseiulus californicus was less effective at reducing T. urticae numbers, and T. pyri was not effective; no interaction between predator species was detected in these experiments. When T. urticae alone was present as prey on potted plants, P. persimilis and N. californicus were the only phytoseiids to significantly reduce T. urticae numbers. These two predator species provided effective control of T. urticae when P. pallidus was also present; however, none of the predators reduced numbers of P. pallidus. There were no significant negative interactions when different species of predators were present together on these potted plants. In field experiments, releases of both P. persimilis and N. cucumeris significantly reduced T. urticae numbers. However, there was a significant interaction between these predator species, leading to poorer control of T. urticae when both species were released together. These results show the importance of conducting predator/prey feeding tests at different spatial scales. PMID:17713859

Fitzgerald, Jean; Pepper, Nicola; Easterbrook, Mike; Pope, Tom; Solomon, Mike

2007-01-01

369

Impairment of trophic interactions between zebrafish (Danio rerio) and midge larvae (Chironomus riparius) by chlorpyrifos.  

PubMed

The effects of chemicals on biotic interactions, such as competition and predation, have rarely been investigated in aquatic ecotoxicology. This study presents a new approach for the investigation of predator-prey interactions between zebrafish (Danio rerio) and midge larvae (Chironomus riparius) impaired by chlorpyrifos (CHP), a neurotoxic insecticide. With a simple experimental design including four different treatments: (1) control, (2) predator exposed, (3) prey exposed and (4) both, predator and prey, exposed, we were able to detect by visual observation an increase in the feeding rate of zebrafish preying on exposed chironomids after acute (2 h) exposure to 6 ?g/l CHP. Previously, a decrease in the burrowing behaviour of exposed chironomid larvae was observed. However, when pre-exposing simultaneously both predators and prey, no significant differences in the feeding rate of zebrafish were observed. This suggests an impairment in prey recognition of the exposed zebrafish. At a lower CHP concentration (1 ?g/l), no differences in feeding rate of zebrafish were observed. We therefore propose the use of trophic interactions as parameters in higher tier studies for chemical testing and evaluation of ecotoxicological risk assessment. PMID:20628814

Langer-Jaesrich, Miriam; Kienle, Cornelia; Köhler, Heinz-R; Gerhardt, Almut

2010-10-01

370

[Role of allelopathic compositions in the regulation and development of legume-rhizobial symbiosis].  

PubMed

It was discovered that aromatic compounds isolated from root exudates of three legume species (Pisum sativum L., Vicia faba L. var. major Hartz, and Glycine max L. MERR) and identified as N-phenyl-2-naphthyl amine, dibutyl, and dioctyl esters of orthophthalic acid, which are known to work as negative allelopathic substances, are involved in the regulation of legume-rhizobial symbiosis formation after the inoculation of roots with rhizobia under unfavorable conditions for symbiosis. PMID:23035572

Makarova, L E; Smirnov, V I; Klyba, L V; Petrova, I G; Dudareva, L V

2012-01-01

371

Synthetic ecosystems based on airborne inter- and intrakingdom communication.  

PubMed

Intercellular communication within an organism, between populations, or across species and kingdoms forms the basis of many ecosystems in which organisms coexist through symbiotic, parasitic, or predator-prey relationships. Using multistep airborne communication and signal transduction, we present synthetic ecosystems within a mammalian cell population, in mice, or across species and kingdoms. Inter- and intrakingdom communication was enabled by using sender cells that produce volatile aldehydes, small vitamin-derived molecules, or antibiotics that diffuse, by gas or liquid phase, to receiver cells and induce the expression of specific target genes. Intercellular and cross-kingdom communication was shown to enable quorum sensing between and among mammalian cells, bacteria, yeast, and plants, resulting in precise spatiotemporal control of IFN-beta production. Interconnection of bacterial, yeast, and mammalian cell signaling enabled the construction of multistep signal transduction and processing networks as well as the design of synthetic ecosystems that mimic fundamental coexistence patterns in nature, including symbiosis, parasitism, and oscillating predator-prey interactions. PMID:17551014

Weber, Wilfried; Daoud-El Baba, Marie; Fussenegger, Martin

2007-06-19

372

RAM1 and RAM2 function and expression during Arbuscular Mycorrhizal Symbiosis and Aphanomyces euteiches colonization  

PubMed Central

The establishment of the symbiotic interaction between plants and arbuscular mycorrhizal (AM) fungi requires a very tight molecular dialogue. Most of the known plant genes necessary for this process are also required for nodulation in legume plants and only very recently genes specifically required for AM symbiosis have been described. Among them we identified RAM (Reduced Arbuscular Mycorrhization)1 and RAM2, a GRAS transcription factor and a GPAT respectively, which are critical for the induction of hyphopodia formation in AM fungi. RAM2 function is also required for appressoria formation by the pathogen Phytophtora palmivora. Here we investigated the activity of RAM1 and RAM2 promoters during mycorrhization and the role of RAM1 and RAM2 during infection by the root pathogen Aphanomyces euteiches. pRAM1 is activated without cell type specificity before hyphopodia formation, while pRAM2 is specifically active in arbusculated cells providing evidence for a potential function of cutin momomers in the regulation of arbuscule formation. Furthermore, consistent with what we observed with Phytophtora, RAM2 but not RAM1 is required during Aphanomyces euteiches infection. PMID:24270627

Gobbato, Enrico; Wang, Ertao; Higgins, Gillian; Bano, Syeda Asma; Henry, Christine; Schultze, Michael; Oldroyd, Giles ED

2013-01-01

373

A single-cell view of ammonium assimilation in coral-dinoflagellate symbiosis  

PubMed Central

Assimilation of inorganic nitrogen from nutrient-poor tropical seas is an essential challenge for the endosymbiosis between reef-building corals and dinoflagellates. Despite the clear evidence that reef-building corals can use ammonium as inorganic nitrogen source, the dynamics and precise roles of host and symbionts in this fundamental process remain unclear. Here, we combine high spatial resolution ion microprobe imaging (NanoSIMS) and pulse-chase isotopic labeling in order to track the dynamics of ammonium incorporation within the intact symbiosis between the reef-building coral Acropora aspera and its dinoflagellate symbionts. We demonstrate that both dinoflagellate and animal cells have the capacity to rapidly fix nitrogen from seawater enriched in ammonium (in less than one hour). Further, by establishing the relative strengths of the capability to assimilate nitrogen for each cell compartment, we infer that dinoflagellate symbionts can fix 14 to 23 times more nitrogen than their coral host cells in response to a sudden pulse of ammonium-enriched seawater. Given the importance of nitrogen in cell maintenance, growth and functioning, the capability to fix ammonium from seawater into the symbiotic system may be a key component of coral nutrition. Interestingly, this metabolic response appears to be triggered rapidly by episodic nitrogen availability. The methods and results presented in this study open up for the exploration of dynamics and spatial patterns associated with metabolic activities and nutritional interactions in a multitude of organisms that live in symbiotic relationships. PMID:22222466

Pernice, Mathieu; Meibom, Anders; Van Den Heuvel, Annamieke; Kopp, Christophe; Domart-Coulon, Isabelle; Hoegh-Guldberg, Ove; Dove, Sophie

2012-01-01

374

[Symbiosis between the nodule bacterium Sinorhizobium meliloti and alfalfa (Medicago sativa) under salinization conditions].  

PubMed

Two hundred forty-three isolates of alfalfa nodule bacteria (Sinorhizobium meliloti) were obtained from legume nodules and soils sampled in the northern Aral region, experiencing secondary salinization. Isolates obtained from nodules (N isolates) were significantly more salt-tolerant than those from soils (S isolates) when grown in a liquid medium with 3.5% NaCl. It was found that wild species of alfalfa, melilot, and trigonella preferably formed symbioses with salt-tolerant nodule bacteria in both salinized and nonsalinized soils. Only two alfalfa species, Medicago falcata and M. trautvetteri, formed efficient symbioses in soils contrasting in salinity. The formation of efficient symbiosis with alfalfa in the presence of 0.6% NaCl was studied in 36 isolates (N and S) differing in salt tolerance and symbiotic efficiency. Fifteen isolates formed efficient symbioses in the presence of salt. The increase in the dry weight of the plants was 25-68% higher than in the control group. The efficiency of symbiotic interaction under salinization conditions depended on the efficiency of the isolates under standard conditions but did not correlate with the source of nodule bacteria (soil or nodule) or their salt tolerance. The results indicate that nodule bacterium strains forming efficient symbioses under salinization conditions can be found. PMID:16579450

Ibragimova, M V; Rumiantseva, M L; Onishchuk, O P; Belova, V S; Kurchak, O N; Andronov, E E; Dziubenko, N I; Simarov, B V

2006-01-01

375

SYMBIOSIS (2008) 46, 153160 2008 Balaban, Philadelphia/Rehovot ISSN 0334-5114 Changes in chloroplast structure in lichenized algae  

E-print Network

algae and cyanobacteria are generally reduced to unicellular forms. Both sexual and asexual reproductive, mycobiont, pyrenoid, symbiosis, thallus fragment method 1. Introduction Lichens are symbiotic organisms

376

Combined and interactive effects of global climate change and toxicants on populations and communities.  

PubMed

Increased temperature and other environmental effects of global climate change (GCC) have documented impacts on many species (e.g., polar bears, amphibians, coral reefs) as well as on ecosystem processes and species interactions (e.g., the timing of predator-prey interactions). A challenge for ecotoxicologists is to predict how joint effects of climatic stress and toxicants measured at the individual level (e.g., reduced survival and reproduction) will be manifested at the population level (e.g., population growth rate, extinction risk) and community level (e.g., species richness, food-web structure). The authors discuss how population- and community-level responses to toxicants under GCC are likely to be influenced by various ecological mechanisms. Stress due to GCC may reduce the potential for resistance to and recovery from toxicant exposure. Long-term toxicant exposure can result in acquired tolerance to this stressor at the population or community level, but an associated cost of tolerance may be the reduced potential for tolerance to subsequent climatic stress (or vice versa). Moreover, GCC can induce large-scale shifts in community composition, which may affect the vulnerability of communities to other stressors. Ecological modeling based on species traits (representing life-history traits, population vulnerability, sensitivity to toxicants, and sensitivity to climate change) can be a promising approach for predicting combined impacts of GCC and toxicants on populations and communities. PMID:23147390

Moe, S Jannicke; De Schamphelaere, Karel; Clements, William H; Sorensen, Mary T; Van den Brink, Paul J; Liess, Matthias

2013-01-01

377

COMBINED AND INTERACTIVE EFFECTS OF GLOBAL CLIMATE CHANGE AND TOXICANTS ON POPULATIONS AND COMMUNITIES  

PubMed Central

Increased temperature and other environmental effects of global climate change (GCC) have documented impacts on many species (e.g., polar bears, amphibians, coral reefs) as well as on ecosystem processes and species interactions (e.g., the timing of predator–prey interactions). A challenge for ecotoxicologists is to predict how joint effects of climatic stress and toxicants measured at the individual level (e.g., reduced survival and reproduction) will be manifested at the population level (e.g., population growth rate, extinction risk) and community level (e.g., species richness, food-web structure). The authors discuss how population- and community-level responses to toxicants under GCC are likely to be influenced by various ecological mechanisms. Stress due to GCC may reduce the potential for resistance to and recovery from toxicant exposure. Long-term toxicant exposure can result in acquired tolerance to this stressor at the population or community level, but an associated cost of tolerance may be the reduced potential for tolerance to subsequent climatic stress (or vice versa). Moreover, GCC can induce large-scale shifts in community composition, which may affect the vulnerability of communities to other stressors. Ecological modeling based on species traits (representing life-history traits, population vulnerability, sensitivity to toxicants, and sensitivity to climate change) can be a promising approach for predicting combined impacts of GCC and toxicants on populations and communities. Environ. Toxicol. Chem. 2013;32:49–61. © 2012 SETAC PMID:23147390

Moe, S Jannicke; De Schamphelaere, Karel; Clements, William H; Sorensen, Mary T; Van den Brink, Paul J; Liess, Matthias

2013-01-01

378

Diet of lake trout and burbot in northern Lake Michigan during spring: Evidence of ecological interaction  

USGS Publications Warehouse

We used analyses of burbot (Lota lota) and lake trout (Salvelinus namaycush) diets taken during spring gill-net surveys in northern Lake Michigan in 2006-2008 to investigate the potential for competition and predator-prey interactions between these two species. We also compared our results to historical data from 1932. During 2006-2008, lake trout diet consisted mainly of alewives (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax), whereas burbot utilized a much wider prey base including round goby (Neogobius melanostomus), rainbow smelt, alewives, and sculpins. Using the Schoener's diet overlap index, we found a higher potential for interspecific competition in 1932 than in 2006-2008, though diet overlap was not significant in either time period. No evidence of cannibalism by lake trout or lake trout predation on burbot was found in either time period. In 2006-2008, however, lake trout composed 5.4% (by weight) of burbot diet. To determine whether this predation could be having an impact on lake trout rehabilitation efforts in northern Lake Michigan, we developed a bioenergetic-based consumption estimate for burbot on Boulder Reef (a representative reef within the Northern Refuge) and found that burbot alone can consume a considerable proportion of the yearling lake trout stocked annually, depending on burbot density. Overall, we conclude that predation, rather than competition, is the more important ecological interaction between burbot and lake trout, and burbot predation may be contributing to the failed lake trout rehabilitation efforts in Lake Michigan.

Jacobs, Gregory R.; Madenjian, Charles P.; Bunnell, David B.; Holuszko, Jeffrey D.

2010-01-01

379

The role of iron uptake in pathogenicity and symbiosis in Photorhabdus luminescens TT01  

PubMed Central

Background Photorhabdus are Gram negative bacteria that are pathogenic to insect larvae whilst also having a mutualistic interaction with nematodes from the family Heterorhabditis. Iron is an essential nutrient and bacteria have different mechanisms for obtaining both the ferrous (Fe2+) and ferric (Fe3+) forms of this metal from their environments. In this study we were interested in analyzing the role of Fe3+ and Fe2+ iron uptake systems in the ability of Photorhabdus to interact with its invertebrate hosts. Results We constructed targeted deletion mutants of exbD, feoABC and yfeABCD in P. luminescens TT01. The exbD mutant was predicted to be crippled in its ability to obtain Fe3+ and we show that this mutant does not grow well in iron-limited media. We also show that this mutant was avirulent to the insect but was unaffected in its symbiotic interaction with Heterorhabditis. Furthermore we show that a mutation in feoABC (encoding a predicted Fe2+ permease) was unaffected in both virulence and symbiosis whilst the divalent cation transporter encoded by yfeABCD is required for virulence in the Tobacco Hornworm, Manduca sexta (Lepidoptera) but not in the Greater Wax Moth, Galleria mellonella (Lepidoptera). Moreover the Yfe transporter also appears to have a role during colonization of the IJ stage of the nematode. Conclusion In this study we show that iron uptake (via the TonB complex and the Yfe transporter) is important for the virulence of P. luminescens to insect larvae. Moreover this study also reveals that the Yfe transporter appears to be involved in Mn2+-uptake during growth in the gut lumen of the IJ nematode. Therefore, the Yfe transporter in P. luminescens TT01 is important during colonization of both the insect and nematode and, moreover, the metal ion transported by this pathway is host-dependent. PMID:20569430

2010-01-01

380

Iron: an essential micronutrient for the legume-rhizobium symbiosis.  

PubMed

Legumes, which develop a symbiosis with nitrogen-fixing bacteria, have an increased demand for iron. Iron is required for the synthesis of iron-containing proteins in the host, including the highly abundant leghemoglobin, and in bacteroids for nitrogenase and cytochromes of the electron transport chain. Deficiencies in iron can affect initiation and development of the nodule. Within root cells, iron is chelated with organic acids such as citrate and nicotianamine and distributed to other parts of the plant. Transport to the nitrogen-fixing bacteroids in infected cells of nodules is more complicated. Formation of the symbiosis results in bacteroids internalized within root cortical cells of the legume where they are surrounded by a plant-derived membrane termed the symbiosome membrane (SM). This membrane forms an interface that regulates nutrient supply to the bacteroid. Consequently, iron must cross this membrane before being supplied to the bacteroid. Iron is transported across the SM as both ferric and ferrous iron. However, uptake of Fe(II) by both the symbiosome and bacteroid is faster than Fe(III) uptake. Members of more than one protein family may be responsible for Fe(II) transport across the SM. The only Fe(II) transporter in nodules characterized to date is GmDMT1 (Glycine max divalent metal transporter 1), which is located on the SM in soybean. Like the root plasma membrane, the SM has ferric iron reductase activity. The protein responsible has not been identified but is predicted to reduce ferric iron accumulated in the symbiosome space prior to uptake by the bacteroid. With the recent publication of a number of legume genomes including Medicago truncatula and G. max, a large number of additional candidate transport proteins have been identified. Members of the NRAMP (natural resistance-associated macrophage protein), YSL (yellow stripe-like), VIT (vacuolar iron transporter), and ZIP (Zrt-, Irt-like protein) transport families show enhanced expression in nodules and are expected to play a role in the transport of iron and other metals across symbiotic membranes. PMID:24062758

Brear, Ella M; Day, David A; Smith, Penelope M C

2013-01-01

381

INTERACTIVE OPPONENTS GENERATE INTERESTING GAMES  

Microsoft Academic Search

In this paper we present experiments on neuro- evolution mechanisms applied to predator\\/prey multi-character computer games. Our test-bed is a computer game where the prey (i.e. player) has to avoid its predators by escaping through an exit without getting killed. By viewing the game from the predators' (i.e. opponents') perspective, we attempt off-line to evolve neural-controlled opponents, whose communication is

Georgios N. Yannakakis; John Hallam

382

Emergy-based assessment on industrial symbiosis: a case of Shenyang Economic and Technological Development Zone.  

PubMed

Industrial symbiosis is the sharing of services, utility, and by-product resources among industries. This is usually made in order to add value, reduce costs, and improve the environment, and therefore has been taken as an effective approach for developing an eco-industrial park, improving resource efficiency, and reducing pollutant emission. Most conventional evaluation approaches ignored the contribution of natural ecosystem to the development of industrial symbiosis and cannot reveal the interrelations between economic development and environmental protection, leading to a need of an innovative evaluation method. Under such a circumstance, we present an emergy analysis-based evaluation method by employing a case study at Shenyang Economic and Technological Development Zone (SETDZ). Specific emergy indicators on industrial symbiosis, including emergy savings and emdollar value of total emergy savings, were developed so that the holistic picture of industrial symbiosis can be presented. Research results show that nonrenewable inputs, imported resource inputs, and associated services could be saved by 89.3, 32.51, and 15.7 %, and the ratio of emergy savings to emergy of the total energy used would be about 25.58 %, and the ratio of the emdollar value of total emergy savings to the total gross regional product (GRP) of SETDZ would be 34.38 % through the implementation of industrial symbiosis. In general, research results indicate that industrial symbiosis could effectively reduce material and energy consumption and improve the overall eco-efficiency. Such a method can provide policy insights to industrial park managers so that they can raise appropriate strategies on developing eco-industrial parks. Useful strategies include identifying more potential industrial symbiosis opportunities, optimizing energy structure, increasing industrial efficiency, recovering local ecosystems, and improving public and industrial awareness of eco-industrial park policies. PMID:25023655

Geng, Yong; Liu, Zuoxi; Xue, Bing; Dong, Huijuan; Fujita, Tsuyoshi; Chiu, Anthony

2014-12-01

383

Live imaging of symbiosis: spatiotemporal infection dynamics of a GFP-labelled Burkholderia symbiont in the bean bug Riptortus pedestris  

PubMed Central

Many insects possess endosymbiotic bacteria inside their body, wherein intimate interactions occur between the partners. While recent technological advancements have deepened our understanding of metabolic and evolutionary features of the symbiont genomes, molecular mechanisms underpinning the intimate interactions remain difficult to approach because the insect symbionts are generally uncultivable. The bean bug Riptortus pedestris is associated with the betaproteobacterial Burkholderia symbiont in a posterior region of the midgut, which develops numerous crypts harbouring the symbiont extracellularly. Distinct from other insect symbiotic systems, R. pedestris acquires the Burkholderia symbiont not by vertical transmission but from the environment every generation. By making use of the cultivability and the genetic tractability of the symbiont, we constructed a transgenic Burkholderia strain labelled with green fluorescent protein (GFP), which enabled detailed observation of spatiotemporal dynamics and the colonization process of the symbiont in freshly prepared specimens. The symbiont live imaging revealed that, at the second instar, colonization of the symbiotic midgut M4 region started around 6 h after inoculation (hai). By 24 hai, the symbiont cells appeared in the main tract and also in several crypts of the M4. By 48 hai, most of the crypts were colonized by the symbiont cells. By 72 hai, all the crypts were filled up with the symbiont cells and the symbiont localization pattern continued during the subsequent nymphal development. Quantitative PCR of the symbiont confirmed the infection dynamics quantitatively. These results highlight the stinkbug-Burkholderia gut symbiosis as an unprecedented model for comprehensive understanding of molecular mechanisms underpinning insect symbiosis. PMID:24103110

Kikuchi, Yoshitomo; Fukatsu, Takema

2014-01-01

384

Modelling multi-species interactions in the Barents Sea ecosystem with special emphasis on minke whales and their interactions with cod, herring and capelin  

NASA Astrophysics Data System (ADS)

The Barents Sea ecosystem, one of the most productive and commercially important ecosystems in the world, has experienced major fluctuations in species abundance the past five decades. Likely causes are natural variability, climate change, overfishing and predator-prey interactions. In this study, we use an age-length structured multi-species model (Gadget, Globally applicable Area-Disaggregated General Ecosystem Toolbox) to analyse the historic population dynamics of major fish and marine mammal species in the Barents Sea. The model was used to examine possible effects of a number of plausible biological and fisheries scenarios. The results suggest that changes in cod mortality from fishing or cod cannibalism levels have the largest effect on the ecosystem, while changes to the capelin fishery have had only minor effects. Alternate whale migration scenarios had only a moderate impact on the modelled ecosystem. Indirect effects are seen to be important, with cod fishing pressure, cod cannibalism and whale predation on cod having an indirect impact on capelin, emphasising the importance of multi-species modelling in understanding and managing ecosystems. Models such as the one presented here provide one step towards an ecosystem-based approach to fisheries management.

Lindstrøm, Ulf; Smout, Sophie; Howell, Daniel; Bogstad, Bjarte

2009-10-01

385

Experimental exposure of juvenile snails ( Potamopyrgus antipodarum ?) to infection by trematode larvae ( Microphallus sp.): infectivity, fecundity compensation and growth  

Microsoft Academic Search

Host-parasite interactions that result in host castration are evolutionarily similar to predator-prey interactions because\\u000a both interactions terminate reproduction for the host or prey. Yet, host-parasite interactions differ from predator-prey interactions\\u000a in that infected hosts remain alive and potentially can make adjustments to their life-history strategy before castration\\u000a is complete. Here we exposed juvenile snails (Potamopyrgus antipodarum) to infection by a

Amy C. Krist; Curtis M. Lively

1998-01-01

386

SYMBIOSIS (2007) 43, 7181 2007 Balaban, Philadelphia/Rehovot ISSN 0334-5114 Persistence of heavy metal tolerance of the arbuscular mycorrhizal  

E-print Network

metal tolerance of the arbuscular mycorrhizal fungus Glomus intraradices under different cultivation; Accepted May 31, 2007) Abstract The difference in development of arbuscular mycorrhizal (AM) symbiosis should be recommended to maintain their HM tolerance. Keywords: Mycorrhizal symbiosis, arbuscular

Janouskova, Martina

387

Stress tolerance in plants via habitat-adapted symbiosis.  

PubMed

We demonstrate that native grass species from coastal and geothermal habitats require symbiotic fungal endophytes for salt and heat tolerance, respectively. Symbiotically conferred stress tolerance is a habitat-specific phenomenon with geothermal endophytes conferring heat but not salt tolerance, and coastal endophytes conferring salt but not heat tolerance. The same fungal species isolated from plants in habitats devoid of salt or heat stress did not confer these stress tolerances. Moreover, fungal endophytes from agricultural crops conferred disease resistance and not salt or heat tolerance. We define habitat-specific, symbiotically-conferred stress tolerance as habitat-adapted symbiosis and hypothesize that it is responsible for the establishment of plants in high-stress habitats. The agricultural, coastal and geothermal plant endophytes also colonized tomato (a model eudicot) and conferred disease, salt and heat tolerance, respectively. In addition, the coastal plant endophyte colonized rice (a model monocot) and conferred salt tolerance. These endophytes have a broad host range encompassing both monocots and eudicots. Interestingly, the endophytes also conferred drought tolerance to plants regardless of the habitat of origin. Abiotic stress tolerance correlated either with a decrease in water consumption or reactive oxygen sensitivity/generation but not to increased osmolyte production. The ability of fungal endophytes to confer stress tolerance to plants may provide a novel strategy for mitigating the impacts of global climate change on agricultural and native plant communities. PMID:18256707

Rodriguez, Rusty J; Henson, Joan; Van Volkenburgh, Elizabeth; Hoy, Marshal; Wright, Leesa; Beckwith, Fleur; Kim, Yong-Ok; Redman, Regina S

2008-04-01

388

The dawn of symbiosis between plants and fungi  

PubMed Central

The colonization of land by plants relied on fundamental biological innovations, among which was symbiosis with fungi to enhance nutrient uptake. Here we present evidence that several species representing the earliest groups of land plants are symbiotic with fungi of the Mucoromycotina. This finding brings up the possibility that terrestrialization was facilitated by these fungi rather than, as conventionally proposed, by members of the Glomeromycota. Since the 1970s it has been assumed, largely from the observation that vascular plant fossils of the early Devonian (400 Ma) show arbuscule-like structures, that fungi of the Glomeromycota were the earliest to form mycorrhizas, and evolutionary trees have, until now, placed Glomeromycota as the oldest known lineage of endomycorrhizal fungi. Our observation that Endogone-like fungi are widely associated with the earliest branching land plants, and give way to glomeromycotan fungi in later lineages, raises the new hypothesis that members of the Mucoromycotina rather than the Glomeromycota enabled the establishment and growth of early land colonists. PMID:21389014

Bidartondo, Martin I.; Read, David J.; Trappe, James M.; Merckx, Vincent; Ligrone, Roberto; Duckett, Jeffrey G.

2011-01-01

389

The effects of SO sub 2 on Azolla - Anabaena symbiosis  

SciTech Connect

Cultures of Azolla pinnata containing Anabaena were investigated as a sensitive and reproducible bioindicator of air pollution. Three equal doses of SO{sub 2} (week*ppb: 1*100, 2*50, 4*25) were applied to Azolla cultures growing in nitrogen-free medium in a specially-designed exposure system. Exposure to high concentrations of SO{sub 2} showed highly significant reductions in growth of the fern, while nitrogen fixation and heterocyst development were severely damaged. This was associated with a reduction of protein content in the SO{sub 2}-exposed ferns and again more significant at higher SO{sub 2} levels. There was a variation in the absolute amount of the individual pigments between SO{sub 2} doses and/or treatments which was related to the physiological development of the ferns throughout the fumigations. Moreover, the ratio of violaxanthin to antheraxanthin in the 100 ppb SO{sub 2}-treated ferns was significantly higher than that in the clean air-grown ferns. The results clearly demonstrate that SO{sub 2} has adverse effects on the symbiosis and suggest that this fern is a promising bioindicator of air pollution and a very good model to investigate the inter-relationships between photosynthesis, nitrogen fixation and air pollution stress.

Jaeseoun Hur; Wellburn, A.R. (Lancaster Univ. (United Kingdom))

1991-05-01

390

A microbial symbiosis factor prevents intestinal inflammatory disease.  

PubMed

Humans are colonized by multitudes of commensal organisms representing members of five of the six kingdoms of life; however, our gastrointestinal tract provides residence to both beneficial and potentially pathogenic microorganisms. Imbalances in the composition of the bacterial microbiota, known as dysbiosis, are postulated to be a major factor in human disorders such as inflammatory bowel disease. We report here that the prominent human symbiont Bacteroides fragilis protects animals from experimental colitis induced by Helicobacter hepaticus, a commensal bacterium with pathogenic potential. This beneficial activity requires a single microbial molecule (polysaccharide A, PSA). In animals harbouring B. fragilis not expressing PSA, H. hepaticus colonization leads to disease and pro-inflammatory cytokine production in colonic tissues. Purified PSA administered to animals is required to suppress pro-inflammatory interleukin-17 production by intestinal immune cells and also inhibits in vitro reactions in cell cultures. Furthermore, PSA protects from inflammatory disease through a functional requirement for interleukin-10-producing CD4+ T cells. These results show that molecules of the bacterial microbiota can mediate the critical balance between health and disease. Harnessing the immunomodulatory capacity of symbiosis factors such as PSA might potentially provide therapeutics for human inflammatory disorders on the basis of entirely novel biological principles. PMID:18509436

Mazmanian, Sarkis K; Round, June L; Kasper, Dennis L

2008-05-29

391

Host-bacterial symbiosis in health and disease.  

PubMed

All animals live in symbiosis. Shaped by eons of co-evolution, host-bacterial associations have developed into prosperous relationships creating mechanisms for mutual benefits to both microbe and host. No better example exists in biology than the astounding numbers of bacteria harbored by the lower gastrointestinal tract of mammals. The mammalian gut represents a complex ecosystem consisting of an extraordinary number of resident commensal bacteria existing in homeostasis with the host's immune system. Most impressive about this relationship may be the concept that the host not only tolerates, but has evolved to require colonization by beneficial microorganisms, known as commensals, for various aspects of immune development and function. The microbiota provides critical signals that promote maturation of immune cells and tissues, leading to protection from infections by pathogens. Gut bacteria also appear to contribute to non-infectious immune disorders such as inflammatory bowel disease and autoimmunity. How the microbiota influences host immune responses is an active area of research with important implications for human health. This review synthesizes emerging findings and concepts that describe the mutualism between the microbiota and mammals, specifically emphasizing the role of gut bacteria in shaping an immune response that mediates the balance between health and disease. Unlocking how beneficial bacteria affect the development of the immune system may lead to novel and natural therapies based on harnessing the immunomodulatory properties of the microbiota. PMID:21034976

Chow, Janet; Lee, S Melanie; Shen, Yue; Khosravi, Arya; Mazmanian, Sarkis K

2010-01-01

392

Microgravity effects on the legume/Rhizobium symbiosis  

NASA Astrophysics Data System (ADS)

Symbiotic nitrogen fixation is of critical importance to world agriculture and likely will be a critical part of life support systems developed for prolonged missions in space. Bacteroid formation, an essential step in an effective Dutch White Clover/Rhizobium leguminosarum bv trifolii symbiosis, is induced by succinic acid which is produced by the plant and which is bound and incorporated by the bacterium. Aspirin mimics succinate in its role as a bacteroid inducer and measures of aspirin binding mimiced measurements of succinate binding. In normal gravity (1×g), rhizobium bacteria immediately bound relatively high levels of aspirin (or succinate) in a readily reversible manner. Within a few seconds a portion of this initially bound aspirin became irreversibly bound. In the microgravity environment aboard the NASA 930 aircraft, rhizobia did not display the initial reversible binding of succinate, but did display a similar kinetic pattern of irreversible binding, and ultimately bound 32% more succinate (Acta Astronautica 36:129-133, 1995.) In normal gravity succinate treated cells stop dividing and swell to their maximum size (twice the normal cell volume) within a time equivalent to the time required for two normal cell doublings. Swelling in microgravity was tested in FPA and BPM sample holders aboard the space shuttle (USML-1, and STS-54, 57, and 60.) The behavior of cells in the two sample holders was similar, and swelling behavior of cells in microgravity was identical to behavior in normal gravity.

Urban, James E.

1997-01-01

393

Metabolic symbiosis in cancer: refocusing the Warburg lens.  

PubMed

Using relatively primitive tools in the 1920s, Otto Warburg demonstrated that tumor cells show an increased dependence on glycolysis to meet their energy needs, regardless of whether they were well-oxygenated or not. High rates of glucose uptake, fueling glycolysis, are now used clinically to identify cancer cells. However, the Warburg effect does not account for the metabolic diversity that has been observed amongst cancer cells nor the influences that might direct such diversity. Modern tools have shown that the oncogenes, variable hypoxia levels, and the utilization of different carbon sources affect tumor evolution. These influences may produce metabolic symbiosis, in which lactate from a hypoxic, glycolytic tumor cell population fuels ATP production in the oxygenated region of a tumor. Lactate, once considered a waste product of glycolysis, is an important metabolite for oxidative phosphorylation in many tissues. While much is known about how muscle and the brain use lactate in oxidative phosphorylation, the contribution of lactate in tumor bioenergetics is less defined. A refocused perspective of cancer metabolism that recognizes metabolic diversity within a tumor offers novel therapeutic targets by which cancer cells may be starved from their fuel sources, and thereby become more sensitive to traditional cancer treatments. PMID:22228080

Nakajima, Erica C; Van Houten, Bennett

2013-05-01

394

Thiol-based redox signaling in the nitrogen-fixing symbiosis  

PubMed Central

In nitrogen poor soils legumes establish a symbiotic interaction with rhizobia that results in the formation of root nodules. These are unique plant organs where bacteria differentiate into bacteroids, which express the nitrogenase enzyme complex that reduces atmospheric N 2 to ammonia. Nodule metabolism requires a tight control of the concentrations of reactive oxygen and nitrogen species (RONS) so that they can perform useful signaling roles while avoiding nitro-oxidative damage. In nodules a thiol-dependent regulatory network that senses, transmits and responds to redox changes is starting to be elucidated. A combination of enzymatic, immunological, pharmacological and molecular analyses has allowed us to conclude that glutathione and its legume-specific homolog, homoglutathione, are abundant in meristematic and infected cells, that their spatio-temporally distribution is correlated with the corresponding (homo)glutathione synthetase activities, and that they are crucial for nodule development and function. Glutathione is at high concentrations in the bacteroids and at moderate amounts in the mitochondria, cytosol and nuclei. Less information is available on other components of the network. The expression of multiple isoforms of glutathione peroxidases, peroxiredoxins, thioredoxins, glutaredoxins and NADPH-thioredoxin reductases has been detected in nodule cells using antibodies and proteomics. Peroxiredoxins and thioredoxins are essential to regulate and in some cases to detoxify RONS in nodules. Further research is necessary to clarify the regulation of the expression and activity of thiol redox-active proteins in response to abiotic, biotic and developmental cues, their interactions with downstream targets by disulfide-exchange reactions, and their participation in signaling cascades. The availability of mutants and transgenic lines will be crucial to facilitate systematic investigations into the function of the various proteins in the legume-rhizobial symbiosis. PMID:24133498

Frendo, Pierre; Matamoros, Manuel A.; Alloing, Genevieve; Becana, Manuel

2013-01-01

395

Mechanisms driving change: altered species interactions and ecosystem function through global warming.  

PubMed

1. We review the mechanisms behind ecosystem functions, the processes that facilitate energy transfer along food webs, and the major processes that allow the cycling of carbon, oxygen and nitrogen, and use case studies to show how these have already been, and will continue to be, altered by global warming. 2. Increased temperatures will affect the interactions between heterotrophs and autotrophs (e.g. pollination and seed dispersal), and between heterotrophs (e.g. predators-prey, parasites/pathogens-hosts), with generally negative ramifications for important ecosystem services (functions that provide direct benefit to human society such as pollination) and potential for heightened species co-extinction rates. 3. Mitigation of likely impacts of warming will require, in particular, the maintenance of species diversity as insurance for the provision of basic ecosystem services. Key to this will be long-term monitoring and focused research that seek to maintain ecosystem resilience in the face of global warming. 4. We provide guidelines for pursuing research that quantifies the nexus between ecosystem function and global warming. These include documentation of key functional species groups within systems, and understanding the principal outcomes arising from direct and indirect effects of a rapidly warming environment. Localized and targeted research and monitoring, complemented with laboratory work, will determine outcomes for resilience and guide adaptive conservation responses and long-term planning. PMID:20487086

Traill, Lochran W; Lim, Matthew L M; Sodhi, Navjot S; Bradshaw, Corey J A

2010-09-01

396

Interactive Resource Planning—An Anticipative Concept in the Simulation-Based Decision Support System EXPOSIM  

NASA Astrophysics Data System (ADS)

In our research we intend to use experiments to study human behavior in a simulation environment based on a simple Lotka-Volterra predator-prey ecology. The aim is to study the influence of participants' harvesting strategies and certain personality traits derived from [1] on the outcome in terms of sustainability and economic performance. Such an approach is embedded in a research program which intends to develop and understand interactive resource planning processes. We present the general framework as well as the new decision support system EXPOSIM. The key element is the combination of experimental design, analytical understanding of time-discrete systems (especially Lotka-Volterra systems) and economic performance. In the first part, the general role of laboratory experiments is discussed. The second part summarizes the concept of sustainable development. It is taken from [18]. As we use Lotka-Volterra systems as the basis for our simulations a theoretical framework is described afterwards. It is possible to determine optimal behavior for those systems. The empirical setting is based on the empirical approach that the subjects are put into the position of a decision-maker. They are able to model the environment in such a way that harvesting can be observed. We suggest an experimental setting which might lead to new insights in an anticipatory sense.

Leopold-Wildburger, Ulrike; Pickl, Stefan

2008-10-01

397

R E S E A R C H A R T I C L E Arbuscular mycorrhizal symbiosis can counterbalance the negative  

E-print Network

R E S E A R C H A R T I C L E Arbuscular mycorrhizal symbiosis can counterbalance the negative in-6941.2007.00363.x Editor: Karl Ritz Keywords AM symbiosis; plant diversity; catabolic diversity; Eucalyptus. These results highlight the role of AM symbiosis in the processes involved in soil bio-functioning and plant

Thioulouse, Jean

398

Matching the SYMBIOSIS modules to the list of Competencies for pre-medical undergraduate students with the HHMI-AAMC report, 2009.  

E-print Network

Matching the SYMBIOSIS modules to the list of Competencies for pre-medical undergraduate students in medicine. Since we designed Symbiosis outside the usual confines of curriculum, we wanted to take the list applies to our approach to the laboratories. #12;Refer to Curriculum SYMBIOSIS page for the description

Karsai, Istvan

399

Characterization of Medicago truncatula mutants defective in infection persistence and defense response during Rhizobium-legume symbiosis  

E-print Network

pathway activated during organogenesis and differentiation. Other signals, critical for symbiosis are the exopolysaccharides (EPSs) and lipopolysaccharides (LPSs) (Gray and Rolfe, 1990). Rhizobium mutants with altered LPS structure form ineffective... pathway activated during organogenesis and differentiation. Other signals, critical for symbiosis are the exopolysaccharides (EPSs) and lipopolysaccharides (LPSs) (Gray and Rolfe, 1990). Rhizobium mutants with altered LPS structure form ineffective...

Prabhu, Radhika

2012-06-07

400

The interactive effects of multiple stressors on physiological stress responses and club cell investment in fathead minnows.  

PubMed

Anthropogenic activities have dramatically increased over the past decades, with the consequence that many organisms are simultaneously exposed to multiple stressors. Understanding how organisms respond to these stressors is a key focus for scientists from many disciplines. Here we investigated the interactive effects of two stressors, UV radiation (UVR) and cadmium (Cd) exposure on a common freshwater fish, fathead minnow (Pimephales promelas). UVR is known to influence the density of epidermal club cells (ECCs), which are not only a key component of the innate immune system of fishes, but are also the source of chemical alarm cues that serve to warn other fishes of nearby predators. In contrast, Cd impairs the physiological stress response and ability of fish to respond to alarm cues. We used an integrative approach to examine physiological stress response as well as investment in ECCs. Fish exposed to UVR had higher levels of cortisol than non-exposed controls, but Cd reduced cortisol levels substantially for fish exposed to UVR. Fish exposed to UVR, either in the presence or absence of Cd, showed consistent decreases in ECC investment compared to non-exposed controls. Despite differences in ECC number, there was no difference in the potency of alarm cues prepared from the skin of UVR and Cd exposed or non-exposed fish indicating that UVR and Cd exposure combined may have little influence on chemically-mediated predator-prey interactions. PMID:24463029

Manek, Aditya K; Ferrari, Maud C O; Niyogi, Som; Chivers, Douglas P

2014-04-01

401

Périgord black truffle genome uncovers evolutionary origins and mechanisms of symbiosis.  

PubMed

The Périgord black truffle (Tuber melanosporum Vittad.) and the Piedmont white truffle dominate today's truffle market. The hypogeous fruiting body of T. melanosporum is a gastronomic delicacy produced by an ectomycorrhizal symbiont endemic to calcareous soils in southern Europe. The worldwide demand for this truffle has fuelled intense efforts at cultivation. Identification of processes that condition and trigger fruit body and symbiosis formation, ultimately leading to efficient crop production, will be facilitated by a thorough analysis of truffle genomic traits. In the ectomycorrhizal Laccaria bicolor, the expansion of gene families may have acted as a 'symbiosis toolbox'. This feature may however reflect evolution of this particular taxon and not a general trait shared by all ectomycorrhizal species. To get a better understanding of the biology and evolution of the ectomycorrhizal symbiosis, we report here the sequence of the haploid genome of T. melanosporum, which at approximately 125 megabases is the largest and most complex fungal genome sequenced so far. This expansion results from a proliferation of transposable elements accounting for approximately 58% of the genome. In contrast, this genome only contains approximately 7,500 protein-coding genes with very rare multigene families. It lacks large sets of carbohydrate cleaving enzymes, but a few of them involved in degradation of plant cell walls are induced in symbiotic tissues. The latter feature and the upregulation of genes encoding for lipases and multicopper oxidases suggest that T. melanosporum degrades its host cell walls during colonization. Symbiosis induces an increased expression of carbohydrate and amino acid transporters in both L. bicolor and T. melanosporum, but the comparison of genomic traits in the two ectomycorrhizal fungi showed that genetic predispositions for symbiosis-'the symbiosis toolbox'-evolved along different ways in ascomycetes and basidiomycetes. PMID:20348908

Martin, Francis; Kohler, Annegret; Murat, Claude; Balestrini, Raffaella; Coutinho, Pedro M; Jaillon, Olivier; Montanini, Barbara; Morin, Emmanuelle; Noel, Benjamin; Percudani, Riccardo; Porcel, Bettina; Rubini, Andrea; Amicucci, Antonella; Amselem, Joelle; Anthouard, Véronique; Arcioni, Sergio; Artiguenave, François; Aury, Jean-Marc; Ballario, Paola; Bolchi, Angelo; Brenna, Andrea; Brun, Annick; Buée, Marc; Cantarel, Brandi; Chevalier, Gérard; Couloux, Arnaud; Da Silva, Corinne; Denoeud, France; Duplessis, Sébastien; Ghignone, Stefano; Hilselberger, Benoît; Iotti, Mirco; Marçais, Benoît; Mello, Antonietta; Miranda, Michele; Pacioni, Giovanni; Quesneville, Hadi; Riccioni, Claudia; Ruotolo, Roberta; Splivallo, Richard; Stocchi, Vilberto; Tisserant, Emilie; Viscomi, Arturo Roberto; Zambonelli, Alessandra; Zampieri, Elisa; Henrissat, Bernard; Lebrun, Marc-Henri; Paolocci, Francesco; Bonfante, Paola; Ottonello, Simone; Wincker, Patrick

2010-04-15

402

Stress tolerance in plants via habitat-adapted symbiosis  

USGS Publications Warehouse

We demonstrate that native grass species from coastal and geothermal habitats require symbiotic fungal endophytes for salt and heat tolerance, respectively. Symbiotically conferred stress tolerance is a habitat-specific phenomenon with geothermal endophytes conferring heat but not salt tolerance, and coastal endophytes conferring salt but not heat tolerance. The same fungal species isolated from plants in habitats devoid of salt or heat stress did not confer these stress tolerances. Moreover, fungal endophytes from agricultural crops conferred disease resistance and not salt or heat tolerance. We define habitat-specific, symbiotically-conferred stress tolerance as habitat-adapted symbiosis and hypothesize that it is responsible for the establishment of plants in high-stress habitats. The agricultural, coastal and geothermal plant endophytes also colonized tomato (a model eudicot) and conferred disease, salt and heat tolerance, respectively. In addition, the coastal plant endophyte colonized rice (a model monocot) and conferred salt tolerance. These endophytes have a broad host range encompassing both monocots and eudicots. Interestingly, the endophytes also conferred drought tolerance to plants regardless of the habitat of origin. Abiotic stress tolerance correlated either with a decrease in water consumption or reactive oxygen sensitivity/generation but not to increased osmolyte production. The ability of fungal endophytes to confer stress tolerance to plants may provide a novel strategy for mitigating the impacts of global climate change on agricultural and native plant communities.The ISME Journal (2008) 2, 404-416; doi:10.1038/ismej.2007.106; published online 7 February 2008. ?? 2008 International Society for Microbial Ecology All rights reserved.

Rodriguez, R. J.; Henson, J.; Van Volkenburgh, E.; Hoy, M.; Wright, L.; Beckwith, F.; Kim, Y. -O.; Redman, R. S.

2008-01-01

403

The Light-Organ Symbiosis of Vibrio Fischeri and the Hawaiian Squid, Euprymna Scolopes  

NSDL National Science Digital Library

This informational web page features the luminescent bacteria that live within the light organs of the bobtailed squid and the Hawaiian squid. The page includes a discussion of how symbionts and host influence each others development, bacterial genes required to successfully colonize the squid, the "venting" microenvironment, evidence for oxidative stress occurring inside the light organ, initiation of symbiosis, and the investigators who study the V. fischeri-E. scolopes symbiosis. It also features color images and links to selected reviews and research publications.

Graf, Joerg

2009-06-24

404

Journal of Animal Ecology 2002  

E-print Network

body condition. 2. I studied predation in snowshoe hares (Lepus americanus, Erxleben) when food-words: body condition, Lepus americanus, nutrition, predator­prey interactions, predation, prey selection

405

Understanding the Role of Host Hemocytes in a Squid/Vibrio Symbiosis Using Transcriptomics and Proteomics  

PubMed Central

The symbiosis between the squid, Euprymna scolopes, and the bacterium, Vibrio fischeri, serves as a model for understanding interactions between beneficial bacteria and animal hosts. The establishment and maintenance of the association is highly specific and depends on the selection of V. fischeri and exclusion of non-symbiotic bacteria from the environment. Current evidence suggests that the host’s cellular innate immune system, in the form of macrophage-like hemocytes, helps to mediate host tolerance of V. fischeri. To begin to understand the role of hemocytes in this association, we analyzed these cells by high-throughput 454 transcriptomic and liquid chromatography/tandem mass spectrometry (LC-MS/MS) proteomic analyses. 454 high-throughput sequencing produced 650, 686 reads totaling 279.9?Mb while LC-MS/MS analyses of circulating hemocytes putatively identified 702 unique proteins. Several receptors involved with the recognition of microbial-associated molecular patterns were identified. Among these was a complete open reading frame to a putative peptidoglycan recognition protein (EsPGRP5) with conserved residues for amidase activity. Assembly of the hemocyte transcriptome showed EsPGRP5 had high coverage, suggesting it is among the 5% most abundant transcripts in circulating hemocytes. Other transcripts and proteins identified included members of the conserved NF-?B signaling pathway, putative members of the complement pathway, the carbohydrate binding protein galectin, and cephalotoxin. Quantitative Real-Time PCR of complement-like genes, cephalotoxin, EsPGRP5, and a nitric oxide synthase showed differential expression in circulating hemocytes from adult squid with colonized light organs compared to those isolated from hosts where the symbionts were removed. These data suggest that the presence of the symbiont influences gene expression of the cellular innate immune system of E. scolopes. PMID:22590467

Collins, Andrew J.; Schleicher, Tyler R.; Rader, Bethany A.; Nyholm, Spencer V.

2012-01-01

406

Evolutionary Dynamics of Nitrogen Fixation in the Legume-Rhizobia Symbiosis  

PubMed Central

The stabilization of host–symbiont mutualism against the emergence of parasitic individuals is pivotal to the evolution of cooperation. One of the most famous symbioses occurs between legumes and their colonizing rhizobia, in which rhizobia extract nutrients (or benefits) from legume plants while supplying them with nitrogen resources produced by nitrogen fixation (or costs). Natural environments, however, are widely populated by ineffective rhizobia that extract benefits without paying costs and thus proliferate more efficiently than nitrogen-fixing cooperators. How and why this mutualism becomes stabilized and evolutionarily persists has been extensively discussed. To better understand the evolutionary dynamics of this symbiosis system, we construct a simple model based on the continuous snowdrift game with multiple interacting players. We investigate the model using adaptive dynamics and numerical simulations. We find that symbiotic evolution depends on the cost–benefit balance, and that cheaters widely emerge when the cost and benefit are similar in strength. In this scenario, the persistence of the symbiotic system is compatible with the presence of cheaters. This result suggests that the symbiotic relationship is robust to the emergence of cheaters, and may explain the prevalence of cheating rhizobia in nature. In addition, various stabilizing mechanisms, such as partner fidelity feedback, partner choice, and host sanction, can reinforce the symbiotic relationship by affecting the fitness of symbionts in various ways. This result suggests that the symbiotic relationship is cooperatively stabilized by various mechanisms. In addition, mixed nodule populations are thought to encourage cheater emergence, but our model predicts that, in certain situations, cheaters can disappear from such populations. These findings provide a theoretical basis of the evolutionary dynamics of legume–rhizobia symbioses, which is extendable to other single-host, multiple-colonizer systems. PMID:24691447

Fujita, Hironori; Aoki, Seishiro; Kawaguchi, Masayoshi

2014-01-01

407

Habitat context influences predator interference interactions and the strength of resource partitioning.  

PubMed

Despite increasing evidence that habitat structure can shape predator-prey interactions, few studies have examined the impact of habitat context on interactions among multiple predators and the consequences for combined foraging rates. We investigated the individual and combined effects of stone crabs (Menippe mercenaria) and knobbed whelks (Busycon carica) when foraging on two common bivalves, the hard clam (Mercenaria mercenaria) and the ribbed mussel (Geukensia demissa) in oyster reef and sand flat habitats. Because these species co-occur across these and other estuarine habitats of varying physical complexity, this system is ideal for examining how habitat context influences foraging rates and the generality of predator interactions. Consistent with results from previous studies, consumption rates of each predator in isolation from the other were higher in the sand flat than in the more structurally complex oyster reef habitat. However, consumption by the two predators when combined surprisingly did not differ between the two habitats. This counterintuitive result probably stems from the influence of habitat structure on predator-predator interactions. In the sand-flat habitat, whelks significantly reduced their consumption of their less preferred prey when crabs were present. However, the structurally more complex oyster reef habitat appeared to reduce interference interactions among predators, such that consumption rates when the predators co-occurred did not differ from predation rates when alone. In addition, both habitat context and predator-predator interactions increased resource partitioning by strengthening predator dietary selectivity. Thus, an understanding of how habitat characteristics such as physical complexity influence interactions among predators may be critical to predicting the effects of modifying predator populations on their shared prey. PMID:16705438

Hughes, A Randall; Grabowski, Jonathan H

2006-08-01

408

Can rare positive interactions become common when large carnivores consume livestock?  

PubMed

Livestock populations in protected areas are viewed negatively because of their interaction with native ungulates through direct competition for food resources. However, livestock and native prey can also interact indirectly through their shared predator. Indirect interactions between two prey species occur when one prey modifies either the functional or numerical responses of a shared predator. This interaction is often manifested as negative effects (apparent competition) on one or both prey species through increased predation risk. But indirect interactions can also yield positive effects on a focal prey if the shared predator modifies its functional response toward increased consumption of an abundant and higher-quality alternative prey. Such a phenomenon between two prey species is underappreciated and overlooked in nature. Positive indirect effects can be expected to occur in livestock-dominated wildlife reserves containing large carnivores. We searched for such positive effects in Acacia-Zizhypus forests of India's Gir sanctuary where livestock (Bubalus bubalis and Bos indicus) and a coexisting native prey (chital deer, Axis axis) are consumed by Asiatic lions (Panthera leo persica). Chital vigilance was higher in areas with low livestock density than in areas with high livestock density. This positive indirect effect occurred because lion predation rates on livestock were twice as great where livestock were abundant than where livestock density was low. Positive indirect interactions mediated by shared predators may be more common than generally thought with rather major consequences for ecological understanding and conservation. We encourage further studies to understand outcomes of indirect interactions on long-term predator-prey dynamics in livestock-dominated protected areas. PMID:22624309

Sundararaj, Vijayan; McLaren, Brian E; Morris, Douglas W; Goyal, S P

2012-02-01

409

Complementarity and redundancy of interactions enhance attack rates and spatial stability in host-parasitoid food webs.  

PubMed

Complementary resource use and redundancy of species that fulfill the same ecological role are two mechanisms that can respectively increase and stabilize process rates in ecosystems. For example, predator complementarity and redundancy can determine prey consumption rates and their stability, yet few studies take into account the multiple predator species attacking multiple prey at different rates in natural communities. Thus, it remains unclear whether these biodiversity mechanisms are important determinants of consumption in entire predator-prey assemblages, such that food-web interaction structure determines community-wide consumption and stability. Here, we use empirical quantitative food webs to study the community-wide effects of functional complementarity and redundancy of consumers (parasitoids) on herbivore control in temperate forests. We find that complementarity in host resource use by parasitoids was a strong predictor of absolute parasitism rates at the community level and that redundancy in host-use patterns stabilized community-wide parasitism rates in space, but not through time. These effects can potentially explain previous contradictory results from predator diversity research. Phylogenetic diversity (measured using taxonomic distance) did not explain functional complementarity or parasitism rates, so could not serve as a surrogate measure for functional complementarity. Our study shows that known mechanisms underpinning predator diversity effects on both functioning and stability can easily be extended to link food webs to ecosystem functioning. PMID:25163121

Peralta, Guadalupe; Frost, Carol M; Rand, Tatyana A; Didham, Raphael K; Tylianakis, Jason M

2014-07-01

410

Promoting Industrial Symbiosis Network through Public-Private Partnership: A Case Study of TEDA  

Microsoft Academic Search

As Circular Economy (CE) and sustainable development have been widely recognized in the world, industrial solid waste exchange as a sort of typical industrial symbiosis phenomenon is being opened, mined and utmost importance for resources-saving and environment-friendly society. Commercial businesses and manufacturers are under pressure to be responsible both environmentally and economically in China; the increasing cost of industrial solid

Yu Qi; Huiming Li; Junfeng Wang

2009-01-01

411

Knowing your friends and foes - plant receptor-like kinases as initiators of symbiosis or defence.  

PubMed

The decision between defence and symbiosis signalling in plants involves alternative and modular plasma membrane-localized receptor complexes. A critical step in their activation is ligand-induced homo- or hetero-oligomerization of leucine-rich repeat (LRR)- and/or lysin motif (LysM) receptor-like kinases (RLKs). In defence signalling, receptor complexes form upon binding of pathogen-associated molecular patterns (PAMPs), including the bacterial flagellin-derived peptide flg22, or chitin. Similar mechanisms are likely to operate during the perception of microbial symbiont-derived (lipo)-chitooligosaccharides. The structurally related chitin-oligomer ligands chitooctaose and chitotetraose trigger defence and symbiosis signalling, respectively, and their discrimination involves closely related, if not identical, LysM-RLKs. This illustrates the demand for and the challenges imposed on decision mechanisms that ensure appropriate signal initiation. Appropriate signalling critically depends on abundance and localization of RLKs at the cell surface. This is regulated by internalization, which also provides a mechanism for the removal of activated signalling RLKs. Abundance of the malectin-like domain (MLD)-LRR-RLK Symbiosis Receptor-like Kinase (SYMRK) is additionally controlled by cleavage of its modular ectodomain, which generates a truncated and rapidly degraded RLK fragment. This review explores LRR- and LysM-mediated signalling, the involvement of MLD-LRR-RLKs in symbiosis and defence, and the role of endocytosis in RLK function. PMID:25367611

Antolín-Llovera, Meritxell; Petutsching, Elena Kristin; Ried, Martina Katharina; Lipka, Volker; Nürnberger, Thorsten; Robatzek, Silke; Parniske, Martin

2014-12-01

412

OBSERVATIONS ON THE SYMBIOSIS OF THE SEA ANEMONE STOICHACTIS AND THE POMACENTRID FISH, AMPHIPRION PERCULA  

Microsoft Academic Search

The partnership between certain tropical damselfishes and sea anemones has excited the interest of students of natural history for almost a century. The most significant investigations of the symbiosis have been those of Sluiter (1888), Ver wey (1930) and Gohar (1948), who have given us some knowledge of the ecology and behavioral characteristics of the animals. In 1947 Gudger reviewed

DEMOREST DAVENPORT; KENNETH S. NORRIS

413

The effect of pseudo-microgravity on the symbiosis of plants and microorganisms  

NASA Astrophysics Data System (ADS)

The symbiosis of plants and microorganisms is important to conduct agriculture under space environment. However, we have less knowledge on whether this kind of symbiosis can be established under space condition. We examined the functional compounds responsible to symbiosis between rhizobiaum and Lotus japonicus as a model of symbiotic combination. The existence of the substances for their symbiosis, some flavonoids, have already been known from the study of gene expression, but the detail structures have not yet been elucidated. Pseudomicrogravity was generated by the 3D-clinorotation. Twenty flavonoids were found in the extracts of 16 days plants of Lotus japonicus grown under the normal gravity by HPLC. Content of two flavonoids among them was affected by the infection of Mesorhizobium loti to them. It has a possibility that the two flavonoids were key substances for their combination process. The productions of those flavonoids were confirmed also under the pseudo-microgravity. The amount of one flavonoid was increased by both infection of rhizobium and exposure to the normal and pseudo-micro gravity. Chemical species of these flavonoids were identified by LC- ESI/MS and spectroscopic analysis. To show the effects of pseudo-microgravity on the gene expression, enzymic activities related to the functional compounds are evaluated after the rhizobial infection.

Tomita-Yokotani, Kaori; Maki, Asano; Aoki, Toshio; Tamura, Kenji; Wada, Hidenori; Hashimoto, Hirofumi; Yamashita, Masamichi

414

The promiscuous larvae: flexibility in the establishment of symbiosis in corals  

NASA Astrophysics Data System (ADS)

Coral reefs thrive in part because of the symbiotic partnership between corals and Symbiodinium. While this partnership is one of the keys to the success of coral reef ecosystems, surprisingly little is known about many aspects of coral symbiosis, in particular the establishment and development of symbiosis in host species that acquire symbionts anew in each generation. More specifically, the point at which symbiosis is established (i.e., larva vs. juvenile) remains uncertain, as does the source of free-living Symbiodinium in the environment. In addition, the capacity of host and symbiont to form novel combinations is unknown. To explore patterns of initial association between host and symbiont, larvae of two species of Acropora were exposed to sediment collected from three locations on the Great Barrier Reef. A high proportion of larvae established symbiosis shortly after contact with sediments, and Acropora larvae were promiscuous, taking up multiple types of Symbiodinium. The Symbiodinium types acquired from the sediments reflected the symbiont assemblage within a wide range of cnidarian hosts at each of the three sites, suggesting potential regional differences in the free-living Symbiodinium assemblage. Coral larvae clearly have the capacity to take up Symbiodinium prior to settlement, and sediment is a likely source. Promiscuous larvae allow species to associate with Symbiodinium appropriate for potentially novel environments that may be experienced following dispersal.

Cumbo, V. R.; Baird, A. H.; van Oppen, M. J. H.

2013-03-01

415

Role of Hfq in an animal-microbe symbiosis under simulated microgravity conditions  

NASA Astrophysics Data System (ADS)

Microgravity has a profound impact on the physiology of pathogenic microbes; however, its effects on mutualistic microbes are relatively unknown. To examine the effects of microgravity on those beneficial microbes that associate with animal tissues, we used the symbiosis between the bobtail squid Euprymna scolopes and a motile, luminescent bacterium, Vibrio fischeri as a model system. Specifically, we examined the role of Hfq, an RNA-binding protein known to be an important global regulator under space flight conditions, in the squid-vibrio symbiosis under simulated microgravity. To mimic a reduced gravity environment, the symbiotic partners were co-incubated in high-aspect-ratio rotating wall vessel bioreactors and examined at various stages of development. Results indicated that under simulated microgravity, hfq expression was down-regulated in V. fischeri. A mutant strain defective in hfq showed no colonization phenotype, indicating that Hfq was not required to initiate the symbiosis with the host squid. However, the hfq mutant showed attenuated levels of apoptotic cell death, a key symbiosis phenotype, within the host light organ suggesting that Hfq does contribute to normal light organ morphogenesis. Results also indicated that simulated microgravity conditions accelerated the onset of cell death in wild-type cells but not in the hfq mutant strains. These data suggest that Hfq plays an important role in the mutualism between V. fischeri and its animal host and that its expression can be negatively impacted by simulated microgravity conditions.

Grant, Kyle C.; Khodadad, Christina L. M.; Foster, Jamie S.

2014-01-01

416

Metabolic Complementarity and Genomics of the Dual Bacterial Symbiosis of Sharpshooters  

Microsoft Academic Search

Mutualistic intracellular symbiosis between bacteria and insects is a widespread phenomenon that has contributed to the global success of insects. The symbionts, by provisioning nutrients lacking from diets, allow various insects to occupy or dominate ecological niches that might otherwise be unavailable. One such insect is the glassy-winged sharpshooter (Homalodisca coagulata), which feeds on xylem fluid, a diet exceptionally poor

Dongying Wu; Sean C. Daugherty; Susan E. Van Aken; Grace H. Pai; Kisha L. Watkins; Hoda Khouri; Luke J. Tallon; Jennifer M. Zaborsky; Helen E. Dunbar; Phat L. Tran; Nancy A. Moran; Jonathan A. Eisen

2006-01-01

417

Cleaning symbiosis as an evolutionary game: To cheat or not to cheat?  

Microsoft Academic Search

Cleaning symbiosis is an apparently mutualistic relationship, occurring in diverse taxa, in which cleaners remove ectoparasites from the body of their clients. Here its evolution is explored with a simple game theory model in which both participants play against each other using either honest or cheating strategies. Honest clients pose for cleaners and have their ectoparasites removed, cheating clients eat

Robert Poulin; William L. Vickery

1995-01-01

418

The Mutual Symbiosis between Inclusive Bi-Lingual Education and Multicultural Education  

ERIC Educational Resources Information Center

In this article the authors postulate a mutual symbiosis between multicultural and inclusive bi-lingual education. Combining bi-lingual and multicultural education to create a symbiotic relationship can stimulate reform in schools and can promote inclusive educational systems, thereby keeping native languages and cultures alive for minority…

Irby, Beverly J.; Tong, Fuhui; Lara-Alecio, Rafael

2011-01-01

419

Bacterial genes induced within the nodule during the Rhizobium-legume symbiosis  

Microsoft Academic Search

Summary During the symbiosis between the bacterium Rhizo- bium meliloti and plants such as alfalfa, the bacteria elicit the formation of nodules on the roots of host plants. The bacteria infect the nodule, enter the cyto- plasm of plant cells and differentiate into a distinct cell type called a bacteroid, which is capable of fixing atmospheric nitrogen. To discover bacterial

Valerie Oke; Sharon R. Long

1999-01-01

420

intehweb.com On Pose Estimation for Human-Robot Symbiosis  

Microsoft Academic Search

This paper presents a vision based pose estimation system using knowledge based approach for human- robot symbiosis. The system is based on visual information of the face by connected component analysis of the skin color segmentation of images in HSV color model and is commenced with the face recognition and pose classification scheme using subspace PCA based pattern-matching strategies. With

Chang Hong Liu; Haruki Ueno

421

Possible Roles of Sulfur-Containing Amino Acids in a Chemoautotrophic Bacterium-Mollusc Symbiosis  

E-print Network

Possible Roles of Sulfur-Containing Amino Acids in a Chemoautotrophic Bacterium-Mollusc Symbiosis avoiding its toxic effects. The sulfur-containing free amino acids taurine and thiotaurine may function in sulfide detoxification by serving as sulfur storage compounds or as transport compounds between symbiont

McFall-Ngai, Margaret

422

Mycorrhizal symbiosis increases growth, reproduction and recruitment of Abutilon theophrasti Medic. in the field  

Microsoft Academic Search

We examined in the field the effect of the vesicular-arbuscular (VA) mycorhizal symbiosis on the reproductive success of Abutilon theophrasti Medic., an early successional annual member of the Malvaceae. Mycorrhizal infection greatly enhanced vegetative growth, and flower, fruit and seed production, resulting in significantly greater recruitment the following year. In addition, the seeds produced by mycorrhizal plants were significantly larger

Margot R. Stanley; Roger T. Koide; Durland L. Shumway

1993-01-01

423

The Irreversible Loss of a Decomposition Pathway Marks the Single Origin of an Ectomycorrhizal Symbiosis  

Microsoft Academic Search

Microbial symbioses have evolved repeatedly across the tree of life, but the genetic changes underlying transitions to symbiosis are largely unknown, especially for eukaryotic microbial symbionts. We used the genus Amanita, an iconic group of mushroom-forming fungi engaged in ectomycorrhizal symbioses with plants, to identify both the origins and potential genetic changes maintaining the stability of this mutualism. A multi-gene

Benjamin E. Wolfe; Rodham E. Tulloss; Anne Pringle

2012-01-01

424

Replicon-Dependent Differentiation of Symbiosis-Related Genes in Sinorhizobium Strains Nodulating Glycine max  

PubMed Central

In order to investigate the genetic differentiation of Sinorhizobium strains nodulating Glycine max and related microevolutionary mechanisms, three housekeeping genes (SMc00019, truA, and thrA) and 16 symbiosis-related genes on the chromosome (7 genes), pSymA (6 genes), and pSymB (3 genes) were analyzed. Five distinct species were identified among the test strains by calculating the average nucleotide identity (ANI) of SMc00019-truA-thrA: Sinorhizobium fredii, Sinorhizobium sojae, Sinorhizobium sp. I, Sinorhizobium sp. II, and Sinorhizobium sp. III. These species assignments were also supported by population genetics and phylogenetic analyses of housekeeping genes and symbiosis-related genes on the chromosome and pSymB. Different levels of genetic differentiation were observed among these species or different replicons. S. sojae was the most divergent from the other test species and was characterized by its low intraspecies diversity and limited geographic distribution. Intergenic recombination dominated the evolution of 19 genes from different replicons. Intraspecies recombination happened frequently in housekeeping genes and symbiosis-related genes on the chromosome and pSymB, whereas pSymA genes showed a clear pattern of lateral-transfer events between different species. Moreover, pSymA genes were characterized by a lower level of polymorphism and recombination than those on the chromosome and pSymB. Taken together, genes from different replicons of rhizobia might be involved in the establishment of symbiosis with legumes, but these symbiosis-related genes might have evolved differently according to their corresponding replicons. PMID:24317084

Guo, Hui Juan; Wang, En Tao; Zhang, Xing Xing; Li, Qin Qin; Zhang, Yan Ming; Chen, Wen Xin

2014-01-01

425

Molecular Symbiosis of CHOP and C/EBP? Isoform LIP Contributes to Endoplasmic Reticulum Stress-Induced Apoptosis?  

PubMed Central

Induction of the transcription factor CHOP (CCAAT-binding homologous protein; GADD 153) is a critical cellular response for the transcriptional control of endoplasmic reticulum (ER) stress-induced apoptosis. Upon nuclear translocation, CHOP upregulates the transcription of proapoptotic factors and downregulates antiapoptotic genes. Transcriptional activation by CHOP involves heterodimerization with other members of the basic leucine zipper transcription factor (bZIP) family. We show that the bZIP protein C/EBP? isoform LIP is required for nuclear translocation of CHOP during ER stress. In early ER stress, LIP undergoes proteasomal degradation in the cytoplasmic compartment. During later ER stress, LIP binds CHOP in both cytoplasmic and nuclear compartments and contributes to its nuclear import. By using CHOP-deficient cells and transfections of LIP-expressing vectors in C/EBP??/? mouse embryonic fibroblasts (MEFs), we show that the LIP-CHOP interaction has a stabilizing role for LIP. At the same time, CHOP uses LIP as a vehicle for nuclear import. LIP-expressing C/EBP??/? MEFs showed enhanced ER stress-induced apoptosis compared to C/EBP?-null cells, a finding in agreement with the decreased levels of Bcl-2, a known transcriptional control target of CHOP. In view of the positive effect of CHOP-LIP interaction in mediating their proapoptotic functions, we propose this functional cooperativity as molecular symbiosis between proteins. PMID:20479126

Chiribau, Calin-Bogdan; Gaccioli, Francesca; Huang, Charlie C.; Yuan, Celvie L.; Hatzoglou, Maria

2010-01-01

426

Predation, individual variability and vertebrate population dynamics  

Microsoft Academic Search

Both predation and individual variation in life history traits influence population dynamics. Recent results from laboratory\\u000a predator–prey systems suggest that differences between individuals can also influence predator–prey dynamics when different\\u000a genotypes experience different predation-associated mortalities. Despite the growing number of studies in this field, there\\u000a is no synthesis identifying the overall importance of the interactions between predation and individual heterogeneity

Nathalie Pettorelli; Tim Coulson; Sarah M. Durant; Jean-Michel Gaillard

427

Kankyo kyosei sho energy wo mezashita shintoshi koso. (New city model with environmental symbiosis and energy conservation).  

National Technical Information Service (NTIS)

New city concept is studied from the viewpoints of city economy, environmental symbiosis, energy and resources, transportation, urban disaster prevention, information dissemination, etc. As the result, twelve cluster cities equipped with capabilities of s...

1996-01-01

428

Symbiosis between hydra and chlorella: molecular phylogenetic analysis and experimental study provide insight into its origin and evolution.  

PubMed

Although many physiological studies have been reported on the symbiosis between hydra and green algae, very little information from a molecular phylogenetic aspect of symbiosis is available. In order to understand the origin and evolution of symbiosis between the two organisms, we compared the phylogenetic relationships among symbiotic green algae with the phylogenetic relationships among host hydra strains. To do so, we reconstructed molecular phylogenetic trees of several strains of symbiotic chlorella harbored in the endodermal epithelial cells of viridissima group hydra strains and investigated their congruence with the molecular phylogenetic trees of the host hydra strains. To examine the species specificity between the host and the symbiont with respect to the genetic distance, we also tried to introduce chlorella strains into two aposymbiotic strains of viridissima group hydra in which symbiotic chlorella had been eliminated in advance. We discussed the origin and history of symbiosis between hydra and green algae based on the analysis. PMID:23219706

Kawaida, Hitomi; Ohba, Kohki; Koutake, Yuhki; Shimizu, Hiroshi; Tachida, Hidenori; Kobayakawa, Yoshitaka

2013-03-01

429

Predator cue and prey density interactively influence indirect effects on basal resources in intertidal oyster reefs.  

PubMed

Predators can influence prey abundance and traits by direct consumption, as well as by non-consumptive effects of visual, olfactory, or tactile cues. The strength of these non-consumptive effects (NCEs) can be influenced by a variety of factors, including predator foraging mode, temporal variation in predator cues, and the density of competing prey. Testing the relative importance of these factors for determining NCEs is critical to our understanding of predator-prey interactions in a variety of settings. We addressed this knowledge gap by conducting two mesocosm experiments in a tri-trophic intertidal oyster reef food web. More specifically, we tested how a predatory fish (hardhead catfish, Ariopsis felis) directly influenced their prey (mud crabs, Panopeus spp.) and indirectly affected basal resources (juvenile oysters, Crassostrea virginica), as well as whether these direct and indirect effects changed across a density gradient of competing prey. Per capita crab foraging rates were inversely influenced by crab density, but they were not affected by water-borne predator cues. As a result, direct consumptive effects on prey foraging rates were stronger than non-consumptive effects. In contrast, predator cue and crab density interactively influenced indirect predator effects on oyster mortality in two experiments, with trait-mediated and density-mediated effects of similar magnitude operating to enhance oyster abundance. Consistent differences between a variable predator cue environment and other predator cue treatments (no cue and constant cue) suggests that an understanding of the natural risk environment experienced by prey is critical to testing and interpreting trait-mediated indirect interactions. Further, the prey response to the risk environment may be highly dependent on prey density, particularly in prey populations with strong intra-specific interactions. PMID:22970316

Hughes, A Randall; Rooker, Kelly; Murdock, Meagan; Kimbro, David L

2012-01-01

430

Trophic interactions between two herbivorous insects, Galerucella calmariensis and Myzus lythri, feeding on purple loosestrife, Lythrum salicaria, and two insect predators, Harmonia axyridis and Chrysoperla carnea.  

PubMed

The effects of two herbivorous insects, Galerucella calmariensis Duftschmid and Myzus lythri L. (Coleoptera: Chrysomelidae), feeding on purple loosestrife, Lythrum salicaria L. (Myrtiflorae: Lythraceae), were measured in the presence of two insect predators, Harmonia axyridis Pallas (Coleoptera: Coccinellidae) and Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae). A greenhouse cage experiment examined the direct effects of these predators on these herbivores, and indirect effects of predation on aboveground biomass, defoliation, number of leaves, and internode length. Eight treatment combinations with G. calmariensis, M. lythri, H. axyridis and C. carnea were applied to caged L. salicaria. The experiment ended when G. calmariensis adults were observed, 11 to 13 days after release of first instar G. calmariensis. G. calmariensis larvae alone removed significant amounts of leaf tissue and reduced the number of L. salicaria leaves. Predators did not reduce levels of defoliation by G. calmariensis. C. carnea had no effect on G. calmariensis survival, but H. axyridis reduced G. calmariensis survival in the presence of M. lythri. Both predators reduced the survival of M. lythri. This short duration greenhouse study did not demonstrate that predator-prey interactions altered herbivore effects on L. salicaria. PMID:20302526

Matos, Bethzayda; Obrycki, John J

2007-01-01

431

Symbiosis of sea anemones and hermit crabs: different resource utilization patterns in the Aegean Sea  

NASA Astrophysics Data System (ADS)

The small-scale distribution and resource utilization patterns of hermit crabs living in symbiosis with sea anemones were investigated in the Aegean Sea. Four hermit crab species, occupying shells of nine gastropod species, were found in symbiosis with the sea anemone Calliactis parasitica. Shell resource utilization patterns varied among hermit crabs, with Dardanus species utilizing a wide variety of shells. The size structure of hermit crab populations also affected shell resource utilization, with small-sized individuals inhabiting a larger variety of shells. Sea anemone utilization patterns varied both among hermit crab species and among residence shells, with larger crabs and shells hosting an increased abundance and biomass of C. parasitica. The examined biometric relationships suggested that small-sized crabs carry, proportionally to their weight, heavier shells and increased anemone biomass than larger ones. Exceptions to the above patterns are related either to local resource availability or to other environmental factors.

Vafeiadou, Anna-Maria; Antoniadou, Chryssanthi; Chintiroglou, Chariton

2012-09-01

432

Identification of genes relevant to symbiosis and competitiveness in Sinorhizobium meliloti using signature-tagged mutants.  

PubMed

Sinorhizobium meliloti enters an endosymbiosis with alfalfa plants through the formation of nitrogen-fixing nodules. In order to identify S. meliloti genes required for symbiosis and competitiveness, a method of signature-tagged mutagenesis was used. Two sets, each consisting of 378 signature-tagged mutants with a known transposon insertion site, were used in an experiment in planta. As a result, 67 mutants showing attenuated symbiotic phenotypes were identified, including most of the exo, fix, and nif mutants in the sets. For 38 mutants in genes previously not described to be involved in competitiveness or symbiosis in S. meliloti, attenuated competitiveness phenotypes were tested individually. A large part of these phenotypes was confirmed. Moreover, additional symbiotic defects were observed for mutants in several novel genes such as infection deficiency phenotypes (ilvI and ilvD2 mutants) or delayed nodulation (pyrE, metA, thiC, thiO, and thiD mutants). PMID:18184066

Pobigaylo, Nataliya; Szymczak, Silke; Nattkemper, Tim W; Becker, Anke

2008-02-01

433

Involvement of peroxidases in the Medicago truncatula-Rhizobium meliloti symbiosis  

E-print Network

using microscopic methods. An overview of Rkdzobium ? legume symbiosis Nitrogen is a macronunient necessary for the healthy development of a plant and is one of the nutrients whose availability most frequently limits plant growth. The form...-acetylglucosamines bearing a fatty acid on the non-reducing sugar residue. In addition, the factors can have various substitutions on both the reducing and the non-reducing terminal sugar residues (Denarie and Cullimore, 1993). The nod genes are not expressed in free...

Subramanian, Latha

2012-06-07

434

Heme Synthesis in the Rhizobium-Legume Symbiosis: a Palette for Bacterial and Eukaryotic Pigments  

Microsoft Academic Search

Rhizobiaelicitnitrogen-fixingnodulesonlegumerootscom- posedofhighlydifferentiatedplantandbacterialcells.Sustain- ing symbiosis is energy intensive, and an increase in plant and bacterial heme protein synthesis is an essential feature of nod- ule ontogeny. Symbiotic bacteroids express cytochrome heme proteins as part of an electron transport system that allows vigorous and efficient respiration in the low-O2milieu of nod- ules to support nitrogenfixation. Bacteroid respiration is also dependent on leghemoglobin,

MARK R. O'BRIAN

1996-01-01

435

Onset of symbiosis and distribution patterns of symbiotic dinoflagellates in the larvae of scleractinian corals  

Microsoft Academic Search

The establishment of symbiosis in early developmental stages is important for reef-building corals because of the need for\\u000a photosynthetically derived nutrition. Corals spawn eggs and sperm, or brood planula larvae and shed them into the water. Some\\u000a coral eggs or planulae directly inherit symbiotic dinoflagellates (Symbiodinium spp.) from their parents, while others acquire them at each generation. In most species

Saki Harii; Naoko Yasuda; Mauricio Rodriguez-Lanetty; Takahiro Irie; Michio Hidaka

2009-01-01

436

Comparative Sequence Analysis of the Symbiosis Island of Mesorhizobium loti Strain R7A  

Microsoft Academic Search

The Mesorhizobium loti strain R7A symbiosis island is a 502-kb chromosomally integrated element which transfers to nonsymbiotic mesorhizobia in the environment, converting them to Lotus symbionts. It integrates into a phenylalanine tRNA gene in a process mediated by a P4-type integrase encoded at the left end of the element. We have determined the nucleotide sequence of the island and compared

John T. Sullivan; Jodi R. Trzebiatowski; Ruth W. Cruickshank; Jerome Gouzy; Steven D. Brown; Rachel M. Elliot; Damien J. Fleetwood; Nadine G. McCallum; Uwe Rossbach; Gabriella S. Stuart; Julie E. Weaver; Richard J. Webby; Frans J. de Bruijn; Clive W. Ronson

2002-01-01

437

Medicago truncatula , a model plant for studying the molecular genetics of the Rhizobium -legume symbiosis  

Microsoft Academic Search

Medicago truncatula has all the characteristics required for a concerted analysis of nitrogen-fixing symbiosis withRhizobium using the tools of molecular biology, cellular biology and genetics.M. truncatula is a diploid and autogamous plant has a relatively small genome, and preliminary molecular analysis suggests that allelic\\u000a heterozygosity is minimal compared with the cross-fertilising tetraploid alfalfa (Medicago sativa). TheM. truncatula cultivar Jemalong is

David G. Barker; Sylvie Bianchi; François Blondon; Yvette Dattée; Gérard Duc; Sadi Essad; Pascal Flament; Philippe Gallusci; Gérard Génier; Pierre Guy; Xavier Muel; Jacques Tourneur; Jean Dénarié; Thierry Huguet

1990-01-01

438

Complete Genome Sequence of Bradyrhizobium sp. S23321: Insights into Symbiosis Evolution in Soil Oligotrophs  

PubMed Central

Bradyrhizobium sp. S23321 is an oligotrophic bacterium isolated from paddy field soil. Although S23321 is phylogenetically close to Bradyrhizobium japonicum USDA110, a legume symbiont, it is unable to induce root nodules in siratro, a legume often used for testing Nod factor-dependent nodulation. The genome of S23321 is a single circular chromosome, 7,231,841 bp in length, with an average GC content of 64.3%. The genome contains 6,898 potential protein-encoding genes, one set of rRNA genes, and 45 tRNA genes. Comparison of the genome structure between S23321 and USDA110 showed strong colinearity; however, the symbiosis islands present in USDA110 were absent in S23321, whose genome lacked a chaperonin gene cluster (groELS3) for symbiosis regulation found in USDA110. A comparison of sequences around the tRNA-Val gene strongly suggested that S23321 contains an ancestral-type genome that precedes the acquisition of a symbiosis island by horizontal gene transfer. Although S23321 contains a nif (nitrogen fixation) gene cluster, the organization, homology, and phylogeny of the genes in this cluster were more similar to those of photosynthetic bradyrhizobia ORS278 and BTAi1 than to those on the symbiosis island of USDA110. In addition, we found genes encoding a complete photosynthetic system, many ABC transporters for amino acids and oligopeptides, two types (polar and lateral) of flagella, multiple respiratory chains, and a system for lignin monomer catabolism in the S23321 genome. These features suggest that S23321 is able to adapt to a wide range of environments, probably including low-nutrient conditions, with multiple survival strategies in soil and rhizosphere. PMID:22452844

Okubo, Takashi; Tsukui, Takahiro; Maita, Hiroko; Okamoto, Shinobu; Oshima, Kenshiro; Fujisawa, Takatomo; Saito, Akihiro; Futamata, Hiroyuki; Hattori, Reiko; Shimomura, Yumi; Haruta, Shin; Morimoto, Sho; Wang, Yong; Sakai, Yoriko; Hattori, Masahira; Aizawa, Shin-ichi; Nagashima, Kenji V. P.; Masuda, Sachiko; Hattori, Tsutomu; Yamashita, Akifumi; Bao, Zhihua; Hayatsu, Masahito; Kajiya-Kanegae, Hiromi; Yoshinaga, Ikuo; Sakamoto, Kazunori; Toyota, Koki; Nakao, Mitsuteru; Kohara, Mitsuyo; Anda, Mizue; Niwa, Rieko; Jung-Hwan, Park; Sameshima-Saito, Reiko; Tokuda, Shin-ichi; Yamamoto, Sumiko; Yamamoto, Syuji; Yokoyama, Tadashi; Akutsu, Tomoko; Nakamura, Yasukazu; Nakahira-Yanaka, Yuka; Hoshino, Yuko Takada; Hirakawa, Hideki; Mitsui, Hisayuki; Terasawa, Kimihiro; Itakura, Manabu; Sato, Shusei; Ikeda-Ohtsubo, Wakako; Sakakura, Natsuko; Kaminuma, Eli; Minamisawa, Kiwamu

2012-01-01

439

Visualization of nodulation gene activity on the early stages of Rhizobium leguminosarum bv. viciae symbiosis  

Microsoft Academic Search

A technique was optimized for thein situ detection of nodulation (nod) gene activity inRhizobium leguminosarum bv.viciae symbiosis with compatible plant hostsVicia tetrasperma (L.)Schreb. andPisum sativum L. The transcription ofnodABC-lacZ fusion was visualized as ?-galactosidase (?-Gal) activity after reaction with the chromogenic substrate X-Gal and subsequent\\u000a light microscopy, while the back-ground of the indigenous ?-Gal activity of rhizobia and the host

P. Chovanec; K. Novák

2005-01-01

440

Complete genome sequence of Bradyrhizobium sp. S23321: insights into symbiosis evolution in soil oligotrophs.  

PubMed

Bradyrhizobium sp. S23321 is an oligotrophic bacterium isolated from paddy field soil. Although S23321 is phylogenetically close to Bradyrhizobium japonicum USDA110, a legume symbiont, it is unable to induce root nodules in siratro, a legume often used for testing Nod factor-dependent nodulation. The genome of S23321 is a single circular chromosome, 7,231,841 bp in length, with an average GC content of 64.3%. The genome contains 6,898 potential protein-encoding genes, one set of rRNA genes, and 45 tRNA genes. Comparison of the genome structure between S23321 and USDA110 showed strong colinearity; however, the symbiosis islands present in USDA110 were absent in S23321, whose genome lacked a chaperonin gene cluster (groELS3) for symbiosis regulation found in USDA110. A comparison of sequences around the tRNA-Val gene strongly suggested that S23321 contains an ancestral-type genome that precedes the acquisition of a symbiosis island by horizontal gene transfer. Although S23321 contains a nif (nitrogen fixation) gene cluster, the organization, homology, and phylogeny of the genes in this cluster were more similar to those of photosynthetic bradyrhizobia ORS278 and BTAi1 than to those on the symbiosis island of USDA110. In addition, we found genes encoding a complete photosynthetic system, many ABC transporters for amino acids and oligopeptides, two types (polar and lateral) of flagella, multiple respiratory chains, and a system for lignin monomer catabolism in the S23321 genome. These features suggest that S23321 is able to adapt to a wide range of environments, probably including low-nutrient conditions, with multiple survival strategies in soil and rhizosphere. PMID:22452844

Okubo, Takashi; Tsukui, Takahiro; Maita, Hiroko; Okamoto, Shinobu; Oshima, Kenshiro; Fujisawa, Takatomo; Saito, Akihiro; Futamata, Hiroyuki; Hattori, Reiko; Shimomura, Yumi; Haruta, Shin; Morimoto, Sho; Wang, Yong; Sakai, Yoriko; Hattori, Masahira; Aizawa, Shin-Ichi; Nagashima, Kenji V P; Masuda, Sachiko; Hattori, Tsutomu; Yamashita, Akifumi; Bao, Zhihua; Hayatsu, Masahito; Kajiya-Kanegae, Hiromi; Yoshinaga, Ikuo; Sakamoto, Kazunori; Toyota, Koki; Nakao, Mitsuteru; Kohara, Mitsuyo; Anda, Mizue; Niwa, Rieko; Jung-Hwan, Park; Sameshima-Saito, Reiko; Tokuda, Shin-Ichi; Yamamoto, Sumiko; Yamamoto, Syuji; Yokoyama, Tadashi; Akutsu, Tomoko; Nakamura, Yasukazu; Nakahira-Yanaka, Yuka; Takada Hoshino, Yuko; Hirakawa, Hideki; Mitsui, Hisayuki; Terasawa, Kimihiro; Itakura, Manabu; Sato, Shusei; Ikeda-Ohtsubo, Wakako; Sakakura, Natsuko; Kaminuma, Eli; Minamisawa, Kiwamu

2012-01-01

441

Genetics of symbiosis in Lotus japonicus: recombinant inbred lines, comparative genetic maps, and map position of 35 symbiotic loci.  

PubMed

Development of molecular tools for the analysis of the plant genetic contribution to rhizobial and mycorrhizal symbiosis has provided major advances in our understanding of plant-microbe interactions, and several key symbiotic genes have been identified and characterized. In order to increase the efficiency of genetic analysis in the model legume Lotus japonicus, we present here a selection of improved genetic tools. The two genetic linkage maps previously developed from a